X0305 4 2012-04-25 0 0001212458 PROOFPOINT INC PFPT 0001299074 Meritech Management Associates II L.L.C. 245 LYTTON AVENUE SUITE 350 PALO ALTO CA 94301 0 0 1 0 0001299073 Meritech Capital Associates II L.L.C. 245 LYTTON AVENUE SUITE 350 PALO ALTO CA 94301 0 0 1 0 0001255154 MERITECH CAPITAL AFFILIATES II LP 245 LYTTON AVENUE SUITE 350 PALO ALTO CA 94301 0 0 1 0 0001119133 MERITECH CAPITAL PARTNERS II LP 245 LYTTON AVENUE SUITE 350 PALO ALTO CA 94301 0 0 1 0 0001130610 MCP ENTREPRENEUR PARTNERS II LP 245 LYTTON AVENUE SUITE 350 PALO ALTO CA 94301 0 0 1 0 0001255151 MADERA PAUL S 245 LYTTON AVENUE STE 350 PALO ALTO CA 94301 0 0 1 0 0001255152 GORDON MICHAEL B 245 LYTTON AVENUE STE 350 PALO ALTO CA 94301 0 0 1 0 Common Stock 2012-04-25 4 C 0 3020732 A 3020732 I See footnote 3 Common Stock 2012-04-25 4 C 0 77726 A 77726 I See footnote 4 Common Stock 2012-04-25 4 C 0 23099 A 23099 I See footnote 5 Series C Preferred Stock 2012-04-25 4 C 0 4421291 0 D Common Stock 2210645.5 0 I See footnote 3 Series E Preferred Stock 2012-04-25 4 C 0 707406 0 D Common Stock 355340.6449 0 I See footnote 3 Series F Preferred Stock 2012-04-25 4 C 0 909493 0 D Common Stock 454746.5 0 I See footnote 3 Series C Preferred Stock 2012-04-25 4 C 0 113765 0 D Common Stock 56882.5 0 I See footnote 4 Series E Preferred Stock 2012-04-25 4 C 0 18202 0 D Common Stock 9143.1376 0 I See footnote 4 Series F Preferred Stock 2012-04-25 4 C 0 23402 0 D Common Stock 11701 0 I See footnote 4 Series C Preferred Stock 2012-04-25 4 C 0 33809 0 D Common Stock 16904.5 0 I See footnote 5 Series E Preferred Stock 2012-04-25 4 C 0 5410 0 D Common Stock 2717.5241 0 I See footnote 5 Series F Preferred Stock 2012-04-25 4 C 0 6955 0 D Common Stock 3477.5 0 I See footnote 5 In connection with the closing of the Issuer's initial public offering on April 25, 2012, each share of Series C and Series F Preferred Stock automatically converted into 0.5 shares of Issuer's Common Stock, and each share of Series E Preferred Stock automatically converted into 0.502315 shares of Issuer's Common Stock, for no additional consideration, reflecting an adjustment following a 1-for-2 reverse stock split effected by the Issuer on April 2, 2012. All shares of Common Stock (including fractions thereof) issued upon conversion were aggregated. No fractional share was issued upon the conversion of any share or shares of Preferred Stock. Shares held directly by Meritech Capital Partners II L.P. ("MCP II"). Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of MCP II, and Paul S. Madera and Michael B. Gordon, the managing members of Meritech Management Associates II L.L.C., may be deemed to share voting and dispositive power over the shares held by MCP II. Such persons and entities disclaim beneficial ownership of shares held by MCP II except to the extent of any pecuniary interest therein. Shares held directly by Meritech Capital Affiliates II L.P. "(MCA II"). Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of MCA II, and Paul S. Madera and Michael B. Gordon, the managing members of Meritech Management Associates II L.L.C., may be deemed to share voting and dispositive power over the shares held by MCA II. Such persons and entities disclaim beneficial ownership of shares held by MCA II except to the extent of any pecuniary interest therein. Shares held directly by MCP Entrepreneur Partners II L.P. ("Entrepreneur"). Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of Entrepreneur, and Paul S. Madera and Michael B. Gordon, the managing members of Meritech Management Associates II L.L.C., may be deemed to share voting and dispositive power over the shares held by Entrepreneur. Such persons and entities disclaim beneficial ownership of shares held by Entrepreneur except to the extent of any pecuniary interest therein. None. /s/ Paul S. Madera, as a managing member of Meritech Management Associates II L.L.C. 2012-04-25 /s/ Paul S. Madera, as a managing member of Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C. 2012-04-25 /s/ Paul S. Madera, as a managing member of Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of Meritech Capital Partners II L.P. 2012-04-25 /s/ Paul S. Madera, as a managing member of Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of Meritech Capital Affiliates II L.P. 2012-04-25 /s/ Paul S. Madera, as a managing member of Meritech Management Associates II L.L.C., a managing member of Meritech Capital Associates II L.L.C., the general partner of MCP Entrepreneur Partners II L.P. 2012-04-25 /s/ Paul S. Madera 2012-04-25 /s/ Michael B. Gordon 2012-04-25