Support Agreement, dated as of October 23, 2023, by and among EngageSmart, Inc., Parent and affiliates of Summit

Exhibit 10.2

SUPPORT AGREEMENT

This Support Agreement (this “Agreement”), dated as of October 22, 2023, is entered into by and among EngageSmart, Inc., a Delaware corporation (the “Company”), the undersigned stockholders (collectively, the “Stockholders” and each, a “Stockholder”) and Icefall Parent, LLC, a Delaware limited liability company (“Parent”). Capitalized terms used but not defined herein shall have the meanings given to them in the Merger Agreement (as defined below).

RECITALS

WHEREAS, concurrently with the execution and delivery of this Agreement, (i) the Company, (ii) Parent and (iii) Icefall Merger Sub, Inc., a Delaware corporation and a wholly owned Subsidiary of Parent (“Merger Sub”), are entering into an Agreement and Plan of Merger (as may be amended from time to time, the “Merger Agreement”), which provides for the merger of Merger Sub with and into the Company (the “Merger”) with the Company surviving the Merger as a wholly owned subsidiary of Parent;

WHEREAS, as of the date hereof, each Stockholder is the record and/or “beneficial owner” (within the meaning of Rule 13d-3 under the Exchange Act) of the number of shares of Common Stock, par value $0.001 per share, of the Company (as adjusted pursuant to Section 10, the “Common Stock”) set forth opposite the Stockholder’s name on Exhibit A hereto under the heading “Owned Shares”, being all of the shares of Common Stock owned of record or beneficially by the Stockholder as of the date hereof (as adjusted pursuant to Section 10, collectively, the “Owned Shares”);

WHEREAS, as a condition to the willingness of the Company and Parent to enter into the Merger Agreement and as an inducement and in consideration therefor, the Company and Parent have required that the Stockholders, and the Stockholders have agreed to, enter into this Agreement.

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants and agreements herein contained, and intending to be legally bound hereby, the Stockholders, the Company and Parent hereby agree as follows:

1. Agreement to Vote the Covered Shares; Proxy.

1.1 Beginning on the date hereof until the Termination Date (as defined below), at every meeting of the Company’s stockholders, including any postponement, recess or adjournment thereof, or in any other circumstance, however called, each Stockholder, severally and not jointly, agrees to, and if applicable, to cause its controlled Affiliates to, affirmatively vote (including via proxy) or execute consents, in each case, no later than 10 Business Days following the date on which the definitive Proxy Statement is first filed with the SEC with respect to (or cause to be voted (including via proxy) or consents to be executed with respect to) and not to withdraw or modify any such vote or consent with respect to, all of the Owned Shares and any additional shares of Common Stock or other voting securities of the Company acquired by such Stockholder or its respective controlled Affiliates after the date hereof and prior to the Termination Date (as adjusted pursuant to Section 10, collectively, and together with the Owned Shares, the “Covered Shares”) as follows: (a) in favor of (i) the adoption of the Merger Agreement and the

approval of the Merger, including any amended and restated Merger Agreement or amendment to the Merger Agreement that, in any such case, increases the Per Share Price or otherwise results in the Merger Agreement being objectively more economically favorable to the Company Stockholders than the Merger Agreement in effect as of the date of this Agreement (provided, that any amendment and restatement to the Merger Agreement or amendment to the Merger Agreement that reduces the Per Share Price, changes the form of consideration being offered to Company Stockholders under the Merger Agreement or materially delays the timing of any such payment shall be deemed to be less economically favorable to the Company Stockholders than the Merger Agreement in effect as of the date of this Agreement), (ii) the approval of any proposal to adjourn or postpone any Company Stockholder Meeting to a later date if the Company or Parent proposes or requests such postponement or adjournment in accordance with Section 6.4(b) of the Merger Agreement, and (iii) the approval of any other proposal considered and voted upon by the Company Stockholders at any Company Stockholder Meeting necessary for consummation of the Merger and the other transactions contemplated by the Merger Agreement, and (b) against (i) any proposal, action or agreement that would reasonably be expected to result in a breach of any covenant, representation or warranty or other obligation or agreement of the Company contained in the Merger Agreement or that would reasonably be expected to result in any condition set forth in the Merger Agreement not being satisfied or not being fulfilled prior to the Termination Date, (ii) any Acquisition Proposal or any other proposal made in opposition to or in competition with, or which is inconsistent with, the Merger Agreement or the transactions contemplated thereby, (iii) any recapitalization, reorganization, dissolution, liquidation, winding up or similar extraordinary transaction involving the Company (except as contemplated by the Merger Agreement) and (iv) any other action, agreement or proposal which would reasonably be expected to prevent, materially impede or materially delay the consummation of the Merger or any of the transactions contemplated by the Merger Agreement (clauses (a) and (b) collectively, the “Supported Matters”). Each Stockholder agrees to, and agrees to cause its applicable controlled Affiliates to, be present, in person or by proxy, at every meeting of the Company’s stockholders, including any postponement, recess or adjournment thereof, or in any other circumstance, however called, to vote on the Supported Matters (in the manner described in this Section 1.1) so that all of the Covered Shares will be counted for purposes of determining the presence of a quorum at each such meeting, or otherwise cause the Covered Shares to be counted as present threat for purposes of establishing a quorum at each such meeting. For the avoidance of doubt, except with respect to the Supported Matters, the Stockholders do not have any obligation to vote the Covered Shares in any particular manner and, with respect to matters other than the Supported Matters, the Stockholders shall be entitled to vote the Covered Shares in its sole discretion. The Stockholders shall not take any action that would reasonably be expected to prevent, materially impair or materially delay the consummation of the transactions contemplated by this Agreement or the Merger Agreement. In the event that the Company and Parent agree to effectuate the transactions contemplated by the Merger Agreement by means of a tender offer, each Stockholder shall tender (and shall not withdraw), or cause to be tendered (and cause to not to be withdrawn), all of its Covered Shares pursuant to and in accordance with the terms of such tender offer prior to the time required for such Covered Shares to be validly tendered (and not withdrawn) for acceptance in such tender offer.

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1.2 Proxy. In the event, but only in the event, that any Stockholder fails to comply with any of its obligations set forth in Section 1.1 (as determined in Parent’s sole discretion), then in such event such Stockholder hereby irrevocably appoints, as its proxy and attorney-in-fact, Christina Lema and Gursimarjit Singh, each of them individually, with full power of substitution and resubstitution, to vote such Stockholder’s Covered Shares in accordance with Section 1.1 at the Company Stockholder Meeting (including any postponement, recess or adjournment thereof) in respect of such Stockholder’s Covered Shares (to the extent such Covered Shares are entitled to so vote) prior to the Termination Date at which any Supported Matters are to be considered; provided, however, for the avoidance of doubt, that such Stockholder shall at all times retain the right to vote such Stockholder’s Covered Shares (or to direct how such Covered Shares shall be voted) in such Stockholder’s sole discretion on matters other than Supported Matters in accordance with Section 1.1. This proxy is coupled with an interest, is (or will be, as applicable) given as an additional inducement of Parent to enter into this Agreement and shall be irrevocable prior to the Termination Date, at which time any such proxy shall terminate. Parent may terminate or waive its rights to enforce this proxy with respect to any Stockholder at any time at its sole election by written notice provided to the applicable Stockholder.

2. Termination. This Agreement shall terminate automatically and without further action of the parties hereto upon the earliest to occur of: (i) the valid termination of the Merger Agreement in accordance with its terms, (ii) the Effective Time, (iii) any modification, waiver or amendment to any provision of the Merger Agreement that is effected without the Stockholders’ prior written consent and that reduces the Per Share Price or changes the form of consideration being offered to Company Stockholders under the Merger Agreement, imposes any non-immaterial conditions, requirements or restrictions on any Stockholder’s right to receive the cash consideration payable to such Stockholder with respect to shares of Company Common Stock owned by such Stockholder pursuant to the Merger Agreement or that materially delays the timing of any such payment (the earliest such date set forth in clauses (i) through (iii), the “Termination Date”); provided, that the provisions set forth in Sections 13 through 24 hereof shall survive the termination of this Agreement; provided, further, that the termination of this Agreement shall not prevent any party hereto from seeking any remedies (at law or in equity) against any other party hereto for that party’s Willful and Material Breach of this Agreement that may have occurred on or before such termination. For the purpose hereof, “Willful and Material Breach” means, with respect to any covenant, representation, warranty or other agreement set forth in this Agreement, a material breach that is a consequence of an act or failure to act undertaken or omitted to be taken by the breaching party with the actual or constructive knowledge (which shall be deemed to include knowledge of facts that a Person acting reasonably should have known, based on reasonable due inquiry) that the taking of such act or failure to take such act would, or would reasonably be expected to, cause, or constitute a breach of the relevant covenant, representation, warranty or other agreement.

3. Certain Covenants.

3.1 Acquisition Proposals.

(a) From and after the date hereof until the Termination Date, each Stockholder, severally and not jointly, hereby covenants and agrees that, except as expressly contemplated by this Agreement, such Stockholder shall not, and shall cause its Affiliates, directors, officers, employees, consultants, agents representatives and advisors (collectively, “Representatives”) not to, directly or indirectly, subject to Section 7 hereof in all respects, (i)

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(1) solicit, initiate, propose or induce the making, submission or announcement of, or knowingly encourage, facilitate or assist, any proposal or inquiry that constitutes, or is reasonably expected to lead to, an Acquisition Proposal; (ii) furnish to any Person (other than to Parent or any designees of Parent) any non-public information relating to the Company Group or afford to any Person access to the business, properties, assets, books, records or other non-public information, or to any personnel, of the Company Group (other than Parent or any designees of Parent), in any such case, with the intent to induce the making, submission or announcement of, or to knowingly encourage, facilitate or assist, any proposal or inquiry that constitutes, or is reasonably expected to lead to, an Acquisition Proposal or any inquiries or the making of any proposal that constitutes, or would reasonably be expected to lead to, an Acquisition Proposal; (iii) participate or engage in discussions or negotiations with any Person with respect to any inquiry or proposal that constitutes, or would reasonably be expected to lead to, an Acquisition Proposal (other than informing such Persons of the existence of the provisions contained in this Section 3.1); (iv) approve, endorse or recommend any proposal that constitutes, or would reasonably be expected to lead to, an Acquisition Proposal; (v) enter into any letter of intent, memorandum of understanding, merger agreement, acquisition agreement or other Contract relating to an Acquisition Transaction; (vi) engage in any activities, or assist or facilitate in the engage of any activities, that the Company and its Affiliates and their respective Representatives are permitted to engage in during the Go-Shop Period pursuant to Section 5.3(a) of the Merger Agreement or (vii) authorize or commit to do any of the foregoing. Immediately upon the execution of this Agreement, each Stockholder will cease and cause to be terminated any discussions or negotiations with any Person and its Representatives that would be prohibited by this Section 3.1. Notwithstanding anything to the contrary in this Section 3.1 but subject to Section 7, the Stockholders may participate or engage in discussions or negotiations with, and furnish information and data to, any Person or Group or their respective Representatives that have delivered to the Company a bona fide written unsolicited Acquisition Proposal that did not result from a breach of Section 5.3(a) of the Merger Agreement solely for the purpose of entering into a voting agreement with such Person or Group on substantially similar terms to the terms hereof, in each case, if and only if the Special Committee has determined in good faith (after consultation with its financial advisor and outside legal counsel) that such Acquisition Proposal either constitutes a Superior Proposal or is reasonably likely to lead to a Superior Proposal and the Special Committee has complied with Section 5.3(b) of the Merger Agreement with respect to such Acquisition Proposal.

(b) From and after the date hereof until the Termination Date, each Stockholder (solely in its capacity as a stockholder of the Company) will promptly (and, in any event, within 24 hours from the receipt thereof) notify Parent in writing if any inquiries, offers or proposals in connection with the last sentence of Section 3.1(a), or any discussions or negotiations are sought to be initiated or continued with, such Stockholder or any of its Representatives with respect to an Acquisition Proposal. Such notice must include (i) the identity of the Person or “group” of Persons making such offers or proposals (unless, in each case, such disclosure is prohibited pursuant to the terms of any confidentiality agreement with such Person or “group” of Persons that is in effect on the date of this Agreement); and (ii) a summary of the material terms and conditions of such offers or proposals. Thereafter, each Stockholder must keep Parent reasonably informed, on a prompt basis, of the status (and supplementally provide the terms) of any such offers or proposals (including any amendments thereto) and the status of any such discussions or negotiations. Notwithstanding the foregoing, the Stockholders shall not be required to notify Parent of any discussion or negotiations to the extent the Company has notified Parent thereof.

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3.2 Transfers. Beginning on the date hereof until the Termination Date, each Stockholder hereby covenants and agrees that, except as expressly contemplated by this Agreement, (a) such Stockholder shall not, and shall direct its Affiliates and their respective Representatives not to, directly or indirectly, (i) tender any Covered Shares into any tender or exchange offer, (ii) offer, sell, transfer, assign, exchange, pledge, hypothecate, hedge, gift, loan, encumber or otherwise dispose of (collectively, “Transfer”) or enter into any Contract, option, agreement, understanding or other arrangement with respect to the Transfer of, any Covered Shares or beneficial ownership, voting power or any other interest thereof or therein (including by operation of law), (iii) grant any proxies or powers of attorney, deposit any Covered Shares into a voting trust or enter into a voting agreement with respect to any Covered Shares that is inconsistent with this Agreement, (iv) take an action that would reasonably be expected to prevent or materially impair or materially delay the consummation of the transactions contemplated by this Agreement or the Merger Agreement or (v) commit or agree to take any of the foregoing actions. Any Transfer in violation of this Section 3.2 shall be void ab initio. Notwithstanding anything to the contrary in this Agreement, any Stockholder may transfer any or all of the Covered Shares, in accordance with applicable law, to such Stockholder’s controlled Affiliates; provided, that, prior to and as a condition to the effectiveness of such Transfer, each Person to whom any of such Covered Shares or any interest in any of such Covered Shares is or may be transferred shall have executed and delivered to Parent a counterpart of this Agreement in a form reasonably acceptable to Parent pursuant to which such Affiliate shall be bound by all of the terms and provisions hereof in which case such Affiliate shall be deemed a Stockholder hereunder.

4. Representations and Warranties of the Stockholders. Each Stockholder, severally and not jointly, hereby represents and warrants to Parent and the Company as follows:

4.1 Due Authority. Such Stockholder is a legal entity duly organized, validly existing and in good standing under the laws of its jurisdiction of formation. Such Stockholder has all requisite corporate or other similar power and authority and has taken all corporate or other similar action necessary (including approval by the board of directors or applicable corporate bodies) to execute, deliver, comply with and perform its obligations under this Agreement in accordance with the terms hereof and to consummate the transactions contemplated hereby, and no other action on the part of or vote of holders of any equity securities of such Stockholder is necessary to authorize the execution and delivery of, compliance with and performance by such Stockholder of this Agreement. This Agreement has been duly executed and delivered by such Stockholder and, assuming the due execution and delivery of this Agreement by all of the other parties hereto, constitutes a legal, valid and binding agreement of such Stockholder enforceable against such Stockholder in accordance with its terms, except as such enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium and other similar laws affecting or relating to creditors’ rights generally.

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4.2 No Conflict. The execution and delivery of, compliance with and performance of this Agreement by such Stockholder do not and will not (i) conflict with or result in any violation or breach of any provision of the certificate of formation or operating agreement or similar organizational documents of such Stockholder, (ii) conflict with or result in a violation or breach of any applicable law, (iii) require any consent by any Person under, constitute a default, or an event that, with or without notice or lapse of time or both, would constitute a default under, or cause or permit the termination, cancellation or acceleration of any right or obligation or the loss of any benefit to which such Stockholder is entitled, under any Contract binding upon such Stockholder, or to which any of its properties, rights or other assets are subject or (iv) result in the creation of a lien (other than Permitted Liens) on any of the properties or assets (including intangible assets) of such Stockholder, except in the case of clauses (i), (ii), (iii) and (iv) above, any such violation, breach, conflict, default, termination, acceleration, cancellation or loss that would not, individually or in the aggregate, reasonably be expected to restrict in any material respect, prohibit or impair in any material respect the consummation of the Merger or the performance by such Stockholder of its obligations under this Agreement.

4.3 Consents. No consent, approval, order or authorization of, or registration, declaration or filing with, any Governmental Authority or any other Person, is required by or with respect to such Stockholder in connection with the execution and delivery of this Agreement or the consummation by such Stockholder of the transactions contemplated hereby, except (a) as required by the rules and regulations promulgated under the Exchange Act, the Securities Act, or state securities, takeover and “blue sky” laws, (b) compliance with any applicable requirements of the HSR Act and any applicable foreign Antitrust Laws, (c) the applicable rules and regulations of the SEC or any applicable stock exchange or (d) as would not, individually or in the aggregate, reasonably be expected to restrict in any material respect, prohibit, impair in any material respect or materially delay the consummation of the Merger or the performance by such Stockholder of its obligations under this Agreement.

4.4 Ownership of the Owned Shares. Such Stockholder is, as of the date hereof, the record and beneficial owner of the Owned Shares, all of which are free and clear of any liens, other than those created by this Agreement or arising under applicable securities laws. Such Stockholder does not own, of record or beneficially, any shares of capital stock of the Company, or other rights to acquire shares of capital stock of the Company, in each case other than the Owned Shares. Such Stockholder has the sole right to dispose of the Owned Shares, and none of the Owned Shares is subject to any pledge, disposition, transfer or other agreement, arrangement or restriction, except as contemplated by this Agreement. As of the date hereof, such Stockholder has not entered into any agreement to Transfer any Owned Shares and no person has a right to acquire any of the Owned Shares held by such Stockholder.

4.5 Absence of Litigation. As of the date hereof, there is no legal action pending against, or, to the knowledge of such Stockholder, threatened against or affecting such Stockholder or any of its Affiliates (other than the Company and its Subsidiaries) that would reasonably be expected to prevent, materially delay or materially impair the ability of such Stockholder to perform its obligations under this Agreement.

4.6 Finders Fees. No broker, investment bank, financial advisor or other person is entitled to any broker’s, finder’s, financial adviser’s or similar fee or commission in connection with the transactions contemplated hereby based upon arrangements made by or on behalf of such Stockholder.

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5. Representations and Warranties of the Company. The Company hereby represents and warrants to the Stockholders and Parent as follows:

5.1 Due Authority. The Company is a legal entity duly incorporated, validly existing and in good standing under the laws of its jurisdiction of formation. The Company has all requisite corporate power and authority and has taken all corporate action necessary (including approval by the Company Board (acting on the recommendation of the Special Committee) and the Special Committee) to execute, deliver, comply with and perform its obligations under this Agreement in accordance with the terms hereof and to consummate the transactions contemplated hereby, and no other corporate action by the Company or vote of holders of any class of the capital stock of the Company is necessary to approve and adopt this Agreement. This Agreement has been duly executed and delivered by the Company and, assuming the due execution and delivery of this Agreement by all of the other parties hereto, constitutes a legal, valid and binding agreement of the Company enforceable against the Company in accordance with its terms, except as such enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium and other similar laws affecting or relating to creditors’ rights generally.

5.2 No Conflict. The execution and delivery of, compliance with and performance by the Company of this Agreement do not and will not, other than as provided in the Merger Agreement with respect to the Merger and the other transactions contemplated thereby, (i) conflict with or result in any violation or breach of any provision of the certificate of incorporation or bylaws of the Company or the similar organizational documents of any of its Subsidiaries, (ii) conflict with or result in a violation or breach of any applicable law, (iii) require any consent by any Person under, constitute a default, or an event that, with or without notice or lapse of time or both, would constitute a default under, or cause or permit the termination, cancellation or acceleration of any right or obligation or the loss of any benefit to which the Company and any of its Subsidiaries are entitled, under any Contract binding upon the Company or any of its Subsidiaries, or to which any of their respective properties, rights or other assets are subject or (iv) result in the creation of a lien (other than Permitted Liens) on any of the properties or assets (including intangible assets) of the Company or any of its Subsidiaries, except in the case of clauses (ii), (iii) and (iv) above, any such violation, breach, conflict, default, termination, acceleration, cancellation or loss that would not reasonably be expected to restrict, prohibit or impair the performance by the Company of its obligations under this Agreement.

6. Representations and Warranties of Parent. Parent hereby represents and warrants to the Stockholders and the Company as follows:

6.1 Due Authority. Parent is a legal entity duly incorporated, validly existing and in good standing under the laws of its jurisdiction of formation. Parent has all requisite corporate power and authority and has taken all corporate action necessary (including approval by the board of directors or applicable corporate bodies) to execute, deliver, comply with and perform its obligations under this Agreement in accordance with the terms hereof and to consummate the transactions contemplated hereby, and no other corporate action by Parent or vote of holders of any class of the capital stock of Parent is necessary to approve and adopt this Agreement. This Agreement has been duly executed and delivered by Parent and, assuming the due execution and delivery of this Agreement by all of the other parties hereto, constitutes a legal, valid and binding agreement of Parent enforceable against Parent in accordance with its terms, except as such enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium and other similar laws affecting or relating to creditors’ rights generally.

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6.2 No Conflict. The execution and delivery of, compliance with and performance by Parent of this Agreement do not and will not, other than as provided in the Merger Agreement with respect to the Merger and the other transactions contemplated thereby, (i) conflict with or result in any violation or breach of any provision of the certificate of incorporation or bylaws of Parent or the similar organizational documents of any of its Subsidiaries, (ii) conflict with or result in a violation or breach of any applicable law, (iii) require any consent by any Person under, constitute a default, or an event that, with or without notice or lapse of time or both, would constitute a default under, or cause or permit the termination, cancellation or acceleration of any right or obligation or the loss of any benefit to which Parent and any of its Subsidiaries are entitled, under any Contract binding upon Parent or any of its Subsidiaries, or to which any of their respective properties, rights or other assets are subject or (iv) result in the creation of a lien (other than Permitted Liens) on any of the properties or assets (including intangible assets) of Parent or any of its Subsidiaries, except in the case of clauses (ii), (iii) and (iv) above, any such violation, breach, conflict, default, termination, acceleration, cancellation or loss that would not reasonably be expected to restrict, prohibit or impair the performance by Parent of its obligations under this Agreement.

6.3 Consents. No consent, approval, order or authorization of, or registration, declaration or, (except as required by the rules and regulations promulgated under the Exchange Act, the Securities Act, or state securities, takeover and “blue sky” laws) filing with, any Governmental Authority or any other Person, is required by or with respect to Parent in connection with the execution and delivery of this Agreement or the consummation by Parent of the transactions contemplated hereby, except as would not, individually or in the aggregate, reasonably be expected to restrict, prohibit, impair or delay the consummation of the Merger or the performance by Parent of its obligations under this Agreement.

6.4 Absence of Litigation As of the date hereof, there is no legal action pending against, or, to the knowledge of Parent, threatened against or affecting Parent that would reasonably be expected to prevent, materially delay or materially impair the ability of Parent to perform its obligations under this Agreement.

7. Stockholder Capacity. This Agreement is being entered into by each Stockholder solely in its capacity as a record and/or beneficial owner of the Owned Shares, and nothing in this Agreement shall restrict or limit the ability of any Stockholder or any of its Affiliates or Representatives who is a director or officer of the Company (including as a member of the Special Committee) or any of the Company’s Subsidiaries (or any other Representative of the Stockholder or any of its Affiliates acting on behalf of or at the direction of such director or officer in furtherance of his or her duties as a director or officer) from taking, or refraining from taking, any action in his or her capacity as a director or officer of the Company (including as a member of the Special Committee) or any of the Company’s Subsidiaries, including the exercise of fiduciary duties to the Company or its stockholders, and any such action taken in such capacity or any such inaction shall not constitute a breach of this Agreement, including, for the avoidance of doubt, with respect to taking actions pursuant to Section 5.3(a) of the Merger Agreement.

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8. Non-Survival of Representations, Warranties and Covenants. Other than the covenants and agreements in Section 9 and Section 24, which shall survive the Effective Time in accordance with their terms, the representations, warranties and covenants contained herein shall not survive the Effective Time.

9. Waiver of Appraisal and Dissenter Rights and Certain Other Actions. Each Stockholder hereby irrevocably and unconditionally waives, to the fullest extent of applicable law, and agrees to cause to be waived and not to assert any appraisal rights, any dissenter’s rights and any similar rights under Section 262 of the DGCL or otherwise with respect to the Covered Shares with respect to the Merger and the transactions contemplated by the Merger Agreement. Each Stockholder, severally and not jointly, on behalf of itself and its Affiliates and their respective Representatives, agrees not to commence or participate in, and to take all actions necessary to opt out of any class in any class action with respect to, any claim, derivative or other Proceeding, against Parent, Merger Sub, the Company or any of their respective successors relating to the negotiation, execution or delivery of this Agreement or the Merger Agreement or the consummation of the Merger, including any Proceeding (x) challenging the validity of, or seeking to enjoin the operation of, any provision of this Agreement or (y) alleging a breach of any fiduciary duty of the Company Board or the Special Committee in connection with the Merger Agreement, the Merger or the other transactions contemplated thereby. The Stockholders and the Company agree that, with respect to the Stockholders, that certain Stockholders Agreement, dated September 22, 2021, among the Company, General Atlantic (IC), L.P. together with its affiliated investment entities, Summit Partners Growth Equity Fund VIII-A, L.P., Summit Partners Growth Equity Fund VIII-B, L.P., Summit Partners Entrepreneur Advisors Fund I, L.P., Summit Investors I, LLC, Summit Investors I (UK), L.P. (as amended, supplemented or modified from time to time) is hereby terminated (including with respect to any provisions thereof that purport to survive such termination) effective as of the Effective Time.

10. Certain Adjustments. In the event of a stock split, stock dividend or distribution, or any change in the Common Stock by reason of any split-up, reverse stock split, recapitalization, combination, reclassification, exchange of shares or the like, the terms “Common Stock”, “Covered Shares” and “Owned Shares” shall be deemed to refer to and include such shares as well as all such stock dividends and distributions and any securities into which or for which any or all of such shares may be changed or exchanged or which are received in such transaction.

11. Further Assurances. Each Stockholder shall, from time to time, execute and deliver, or cause to be executed and delivered, such additional or further consents, documents and other instruments as Parent or the Company may reasonably request to the extent necessary to effect the transactions contemplated by this Agreement.

12. Notices. All notices and other communications under this Agreement must be in writing and will be deemed to have been duly delivered and received using one or a combination of the following methods: (i) four (4) Business Days after being sent by registered or certified mail, return receipt requested, postage prepaid; (ii) one (1) Business Day after being sent for next Business Day delivery, fees prepaid, via a reputable nationwide overnight courier service; (iii) immediately upon delivery by hand; or (iv) on the date sent by email. In each case, the intended recipient is set forth below:

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if to Stockholders to:

c/o Summit Partners, L.P.

222 Berkely Street, 18th Floor

Boston, MA 02116

Attn: Christopher J. Dean and Matthew G. Hamilton

Email: ***@***; ***@***

if to Parent to:

Icefall Parent, LLC

c/o Vista Equity Partners Management, LLC

Four Embarcadero Center, 20th Floor

San Francisco, CA 94111

with a copy (which will not constitute notice) to:

Kirkland & Ellis LLP

601 Lexington Avenue

New York, New York 10022

Kirkland & Ellis LLP

555 California Street

San Francisco, CA 94104

if to the Company (prior to the Effective Time) to:

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EngageSmart, Inc.

30 Braintree Hill Office Park

Suite 101

Braintree, Massachusetts 02184

with a copy (which will not constitute notice) to:

Skadden, Arps, Slate, Meagher & Flom LLP

500 Boylston Street

Boston, Massachusetts 02116

13. Interpretation. Where a reference in this Agreement is made to a section or exhibit, such reference shall be to a section of or exhibit to this Agreement unless otherwise indicated. If a term is defined as one part of speech (such as a noun), it shall have a corresponding meaning when used as another part of speech (such as a verb). Unless the context of this Agreement clearly requires otherwise, words importing the masculine gender shall include the feminine and neutral genders and vice versa, and the definitions of terms contained in this Agreement are applicable to the singular as well as the plural forms of such terms. The words “includes” or “including” shall mean “including without limitation,” the words “hereof,” “hereby,” “herein,” “hereunder” and similar terms in this Agreement shall refer to this Agreement as a whole and not any particular section or article in which such words appear, the word “extent” in the phrase “to the extent” shall mean the degree to which a subject or other thing extends and such phrase shall not mean simply “if,” any reference to a law shall include any rules and regulations promulgated thereunder, and any reference to any law in this Agreement shall mean such law as from time to time amended, modified or supplemented. Each reference to a “wholly owned Subsidiary” or “wholly owned Subsidiaries” of a Person shall be deemed to include any Subsidiary of such Person where all of the equity interests of such Subsidiary are directly or indirectly owned by such Person (other than directors qualifying shares, nominee shares or other equity interests that are required by law or regulation to be held by a director or nominee).

14. Entire Agreement. This Agreement (along with the documents referenced herein) and the Merger Agreement collectively constitute the entire agreement, and supersede all other prior agreements, understandings, representations and warranties both written and oral, among the parties hereto, with respect to the subject matter hereof.

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15. No Third-Party Beneficiaries. This Agreement shall be binding upon and inure solely to the benefit of the parties hereto and their respective successors and permitted assigns, and except as set forth herein, nothing in this Agreement, express or implied, is intended to or shall confer upon any other Person any right, benefit or remedy of any nature whatsoever under or by reason of this Agreement.

16. Governing Law; Waiver of Jury Trial. This Agreement is governed by and construed in accordance with the laws of the State of Delaware without giving effect to any choice or conflict of law provision or rule (whether of the State of Delaware or any other jurisdiction) that would cause or permit the application of laws of any jurisdictions other than those of the State of Delaware. Each of the parties (i) irrevocably consents to the service of the summons and complaint and any other process (whether inside or outside the territorial jurisdiction of the Chosen Courts) in any Legal Proceeding arising out of or relating to this Agreement, for and on behalf of itself or any of its properties or assets, in accordance with Section 12 or in such other manner as may be permitted by applicable law, but nothing in this Section 16 will affect the right of any party to serve legal process in any other manner permitted by applicable law; (ii) irrevocably and unconditionally consents and submits itself and its properties and assets in any Legal Proceeding to the exclusive general jurisdiction of the Chosen Courts in the event that any dispute or controversy arises out of or relates to this Agreement; (iii) irrevocably and unconditionally agrees that it will not attempt to deny or defeat such personal jurisdiction by motion or other request for leave from any Chosen Court; (iv) agrees that any Legal Proceeding arising out of or relating to this Agreement will be brought, tried and determined only in the Chosen Courts; (v) waives any objection that it may now or hereafter have to the venue of any such Legal Proceeding in the Chosen Courts or that such Legal Proceeding was brought in an inconvenient court and agrees not to plead or claim the same; and (vi) agrees that it will not bring any Legal Proceeding arising out of or relating to this Agreement in any court other than the Chosen Courts. Each of the parties agrees that a final judgment in any Legal Proceeding in the Chosen Courts will be conclusive and may be enforced in other jurisdictions by suit on the judgment or in any other manner provided by applicable law. EACH PARTY ACKNOWLEDGES AND AGREES THAT ANY CONTROVERSY THAT MAY ARISE PURSUANT TO THIS AGREEMENT IS LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES, AND THEREFORE EACH PARTY IRREVOCABLY AND UNCONDITIONALLY WAIVES TO THE FULLEST EXTENT PERMITTED BY LAW ANY RIGHT THAT SUCH PARTY MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LEGAL PROCEEDING (WHETHER FOR BREACH OF CONTRACT, TORTIOUS CONDUCT OR OTHERWISE) DIRECTLY OR INDIRECTLY ARISING OUT OF OR RELATING TO THIS AGREEMENT, AND THE TRANSACTIONS CONTEMPLATED BY THIS AGREEMENT. EACH PARTY CERTIFIES AND AGREES THAT (a) NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVER; (b) IT UNDERSTANDS AND HAS CONSIDERED THE IMPLICATIONS OF THIS WAIVER; (c) IT MAKES THIS WAIVER VOLUNTARILY; AND (d) IT HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION 16.

17. Assignment; Successors. Other than as provided herein, neither this Agreement nor any of the rights, interests or obligations under this Agreement may be assigned or delegated, in whole or in part, by operation of law or otherwise, by any party hereto without the prior written consent of the other parties hereto, and any such assignment without such prior written consent shall be null and void. Subject to the preceding sentence, this Agreement will be binding upon, inure to the benefit of, and be enforceable by, the parties hereto and their respective successors and assigns.

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18. Enforcement. The parties hereto agree that irreparable damage for which monetary damages, even if available, would not be an adequate remedy would occur in the event that the parties hereto do not perform the provisions of this Agreement (including any party hereto failing to take such actions that are required of it hereunder in order to consummate this Agreement) in accordance with its specified terms or otherwise breach such provisions. The parties hereto acknowledge and agree that (a) the parties hereto will be entitled, in addition to any other remedy to which they are entitled at law or in equity, to an injunction, specific performance and other equitable relief to prevent breaches (or threatened breaches) of this Agreement or to enforce specifically the terms and provisions hereof and without bond or other security being required, (b) if any party hereto is seeking injunctive relief, specific performance or other equitable relief pursuant hereto, the other parties hereto will not assert that a remedy of monetary damages would provide an adequate remedy for such breach and (c) the right of specific enforcement is an integral part of the transactions contemplated hereby and without that right, none of the Company, Parent or the Stockholders would have entered into this Agreement. Notwithstanding the foregoing, nothing herein shall in any way limit a party’s right to pursue a claim for monetary damages arising out of a breach of this Agreement.

19. Non-Recourse. This Agreement may only be enforced against, and any Action based upon, arising out of, or related to this Agreement, or the negotiation, execution or performance of this Agreement, may only be brought against the entities that are expressly named as parties hereto and then only with respect to the specific obligations set forth herein with respect to such party. No past, present or future director, officer, employee, incorporator, manager, member, general or limited partner, stockholder, equityholder, controlling person, Affiliate, agent, attorney or other Representative of any party hereto or any of their successors or permitted assigns or any direct or indirect director, officer, employee, incorporator, manager, member, general or limited partner, stockholder, equityholder, controlling person, Affiliate, agent, attorney, Representative, successor or permitted assign of any of the foregoing (each, a “Non-Recourse Party”), shall have any liability to any Stockholder, Parent or the Company for any obligations or liabilities of any party under this Agreement or for any Legal Proceeding (whether in tort, contract or otherwise) based on, in respect of or by reason of the transactions contemplated hereby or in respect of any written or oral representations made or alleged to be made in connection herewith. Each Non-Recourse Party is an express third-party beneficiary of this Section 19.

20. Severability. In the event that any provision of this Agreement, or the application thereof, becomes or is declared by a court of competent jurisdiction to be illegal, void or unenforceable, the remainder of this Agreement will continue in full force and effect and the application of such provision to other Persons or circumstances will be interpreted so as reasonably to effect the intent of the parties hereto. The parties hereto further agree to replace such void or unenforceable provision of this Agreement with a valid and enforceable provision that will achieve, to the extent possible, the economic, business and other purposes of such void or unenforceable provision.

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21. Counterparts. This Agreement and any amendments hereto may be executed in one or more counterparts, all of which will be considered one and the same agreement and will become effective when one or more counterparts have been signed by each of the parties hereto and delivered to the other parties hereto, it being understood that all parties hereto need not sign the same counterpart. Any such counterpart, to the extent delivered by electronic delivery, will be treated in all manners and respects as an original executed counterpart and will be considered to have the same binding legal effect as if it were the original signed version thereof delivered in person. No party hereto may raise the use of an electronic delivery to deliver a signature, or the fact that any signature or agreement or instrument was transmitted or communicated through the use of an electronic delivery, as a defense to the formation of a contract, and each party hereto forever waives any such defense, except to the extent such defense relates to lack of authenticity.

22. Amendment; Waiver. This Agreement may be amended by the parties hereto, and the terms and conditions hereof may be waived, only by an instrument in writing signed on behalf of each of the parties hereto, or, in the case of a waiver, by an instrument signed on behalf of the party waiving compliance. No failure or delay on the part of a party in the exercise of any right or remedy hereunder shall impair such right or power or be construed to be a waiver of, or acquiescence in, any breach of any representation, warranty or agreement herein, nor shall any single or partial exercise of any such right preclude any other or further exercise thereof or of any other right or power.

23. No Presumption Against Drafting Party. The Company, Parent and the Stockholders acknowledge that each party to this Agreement has been represented by counsel in connection with this Agreement and the transactions contemplated by this Agreement. Accordingly, any rule of law or any legal decision that would require interpretation of any claimed ambiguities in this Agreement against the drafting party has no application and is expressly waived.

24. Special Committee Approval. Notwithstanding any provision to the contrary, no amendment or waiver of any provision of this Agreement shall be made by the Company or the Company Board without first obtaining the approval of the Special Committee. The Special Committee shall direct enforcement by the Company of any provisions of this Agreement against the Stockholders.

25. No Agreement until Executed. This Agreement shall not be effective unless and until (i) the Company Board and the Special Committee have approved, for purposes of any applicable anti-takeover laws and regulations, and any applicable provision of the DGCL, the Charter, the Bylaws or any similar organization document of the Company (including Article NINE of the Charter), the Merger Agreement, the Support Agreements and the transactions contemplated by the Merger Agreement, including the Merger, (ii) the Merger Agreement is executed by all parties thereto and (iii) this Agreement is executed and delivered by all parties hereto.

26. No Ownership Interest. Nothing contained in this Agreement shall be deemed to vest in Parent any direct or indirect ownership or incidence of ownership of or with respect to any Covered Shares. All ownership and economic benefits of and relating to the Covered Shares shall remain vested in and belong to the applicable Stockholder.

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[Signature pages follow]

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IN WITNESS WHEREOF, the parties have caused this Agreement to be duly executed and delivered on the date and year first above written.

[Signature Page to Support Agreement]

IN WITNESS WHEREOF, the parties have caused this Agreement to be duly executed and delivered on the date and year first above written.

[Signature Page to Support Agreement]

IN WITNESS WHEREOF, the parties have caused this Agreement to be duly executed and delivered on the date and year first above written.

[Signature Page to Support Agreement]

Exhibit A

Owned Shares