X0306 4 2016-04-26 0 0001212458 PROOFPOINT INC PFPT 0001204818 EVAN DANA L C/O PROOFPOINT, INC. 892 ROSS DRIVE SUNNYVALE CA 94089 1 0 0 0 Common Stock 2016-04-26 4 M 0 1250 4.56 A 6442 D Common Stock 2016-04-26 4 S 0 1250 57.5644 D 5192 D Non-qualified stock option (right to buy) 4.56 2016-04-26 4 M 0 1250 0 D 2018-06-11 Common Stock 1250 5663 D Represents the aggregate of sales effected on the same day at different prices. Represents the weighted average sales price per share. The shares sold at prices ranging from $57.31 to $58.19 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. The stock option is immediately exercisable in full. /s/ Dana Evan By Michael Yang, Attorney-In-Fact 2016-04-28