SUMMIT PARTNERS L P - 07 Mar 2023 Form 4 Insider Report for EngageSmart, Inc.

Footnote F1

Represents (i) 181,406 shares of Common Stock sold by Summit Partners Growth Equity Fund VIII-A, L.P., (ii) 66,271 shares of Common Stock sold by Summit Partners Growth Equity Fund VIII-B, L.P., (iii) 1,203 shares of Common Stock sold by Summit Partners Entrepreneur Advisors Fund I, L.P., (iv) 3,473 shares of Common Stock sold by Summit Investors I, LLC and (v) 374 shares of Common Stock sold by Summit Investors I (UK), L.P. The reported sales were effected pursuant to a full exercise by the underwriters of a greenshoe option of the previously reported underwritten public offering that closed on March 3, 2023.

Footnote F2

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.

Footnote F3

Consists of (i) 17,948,333 shares of Common Stock held by Summit Partners Growth Equity Fund VIII-A, L.P., (ii) 6,556,911 shares of Common Stock held by Summit Partners Growth Equity Fund VIII-B, L.P.,(iii) 119,071 shares of Common Stock held by Summit Partners Entrepreneur Advisors Fund I, L.P., (iv) 343,615 shares of Common Stock held by Summit Investors I, LLC and (v) 37,043 shares of Common Stock held by Summit Investors I (UK), L.P.

Footnote F4

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

Footnote F5

(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.