X0306 4 2023-03-03 0 0001863105 EngageSmart, Inc. ESMT 0000830588 SUMMIT PARTNERS L P 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001514386 Summit Partners Growth Equity Fund VIII-A, L.P. 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001514388 Summit Partners Growth Equity Fund VIII-B, L.P. 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001604887 Summit Partners Entrepreneur Advisors Fund I, L.P. 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001435565 Summit Investors I, LLC 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001494616 Summit Investors I (UK), L.P. 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001627278 SUMMIT MASTER COMPANY, LLC 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001239366 CHUNG PETER Y 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001255670 COLLINS SCOTT C 222 BERKELEY STREET, 18TH FLOOR BOSTON MA 02116 0 0 1 0 Common Stock, par value $0.001 per share 2023-03-03 4 S 0 1669052 18.1925 D 25257700 I See Footnote Represents (i) 1,198,029 shares of Common Stock sold by Summit Partners Growth Equity Fund VIII-A, L.P., (ii) 437,666 shares of Common Stock sold by Summit Partners Growth Equity Fund VIII-B, L.P., (iii) 7,948 shares of Common Stock sold by Summit Partners Entrepreneur Advisors Fund I, L.P., (iv) 22,936 shares of Common Stock sold by Summit Investors I, LLC and (v) 2,473 shares of Common Stock sold by Summit Investors I (UK), L.P. This amount represents a public offering price of $19.00 per share of Common Stock of EngageSmart, Inc. (the "Company"), less an underwriting discount of $0.8075 per share for shares sold in an underwritten public offering. Consists of (i) 18,129,739 shares of Common Stock held by Summit Partners Growth Equity Fund VIII-A, L.P., (ii) 6,623,182 shares of Common Stock held by Summit Partners Growth Equity Fund VIII-B, L.P.,(iii) 120,274 shares of Common Stock held by Summit Partners Entrepreneur Advisors Fund I, L.P., (iv) 347,088 shares of Common Stock held by Summit Investors I, LLC and (v) 37,417 shares of Common Stock held by Summit Investors I (UK), L.P. This amount includes the underwriters' option to purchase up to an additional 252,727 shares of common stock within 30 days of February 28, 2023. Summit Partners, L.P. is the managing member of Summit Partners GE VIII, LLC, which is the general partner of Summit Partners GE VIII, L.P., which is the general partner of each of Summit Partners Growth Equity Fund VIII-A, L.P. and Summit Partners Growth Equity Fund VIII-B, L.P. Summit Master Company, LLC is the (A) sole managing member of Summit Partners Entrepreneur Advisors GP, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund I, L.P., and (B) the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors I, LLC and the general partner of Summit Investors I (UK), L.P. Summit Master Company, LLC, as the sole managing member of Summit Partners Entrepreneur Advisors GP, LLC and the managing member of Summit Investors Management, LLC, (Continued from footnote 4), has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. Investment decisions for Summit Partners, L.P. are made by its two-person Investment Committee, which is currently composed of Scott Collins and Peter Y. Chung. Summit Partners L.P., Scott Collins and Peter Y. Chung each have voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the entities affiliated with Summit Partners, L.P. that are mentioned herein and each of Mr. Collins and Mr. Chung disclaims beneficial ownership of the shares of common stock, in each case, except to the extent of it or his pecuniary interest therein. /s/ Adam H. Hennessey, as attorney-in-fact for Summit Partners Growth Equity Fund VIII-A, L.P. 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Partners Growth Equity Fund VIII-B, L.P. 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Partners Entrepreneur Advisors Fund I, L.P. 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Investors I, LLC 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Investors I (UK), L.P. 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Partners, L.P. 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Summit Master Company, LLC 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Peter Y. Chung 2023-03-03 /s/ Adam H. Hennessey, as attorney-in-fact for Scott Collins 2023-03-03