Sec Form 4 Filing - FEIBER JONATHAN D @ PROOFPOINT INC - 2013-05-07

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person FEIBER JONATHAN D 2. Issuer Name and Ticker or Trading Symbol PROOFPOINT INC [ PFPT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 3000 SAND HILL ROAD, BLDG. 3, SUITE 290 3. Date of Earliest Transaction (MM/DD/YY) 05/07/2013 (Street) MENLO PARK, CA94025 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/07/2013 J( 1 ) 618,485 D $ 0 2,428,849 I See footnote ( 2 ) Common Stock 05/07/2013 J( 3 ) 58,875 D $ 0 2,369,974 I See footnote ( 2 ) Common Stock 05/14/2013 S 22,640 D $ 18.305 ( 4 ) 2,347,334 I See footnote ( 2 ) Common Stock 05/07/2013 J( 5 ) 1,699 A $ 0 1,699 D ( 6 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other FEIBER JONATHAN D 3000 SAND HILL ROAD, BLDG. 3, SUITE 290 MENLO PARK, CA94025 X X Signatures Jonathan Feiber 05/20/2013 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents a pro-rata in-kind distribution by MDV VII, L.P. "MDV" without consideration to its limited partners. ( 2 )Shares directly held by MDV. Jonathan Feiber, a director of the Issuer, and Nancy Schoendorf are managing members of Seventh MDV Partners, L.L.C. ("Seventh"), the general partner of MDV. Each of Jonathan Feiber, Nancy Schoendorf, and Seventh may be deemed to share voting and dispositive power over the shares held by MDV. Mr. Feiber, Ms. Schoendorf, and Seventh disclaim beneficial ownership of the shares held by MDV except to the extent of any pecuniary interest therein. MDV, Seventh, and Ms. Schoendorf are filing a separate Form 4. ( 3 )Represents a pro-rata in-kind distribution by MDV as nominee for MDV VII Leaders Fund, L.P. without consideration to its limited partners. ( 4 )Price reflected is the weighted-average sale price for shares sold in this transaction. The range of sale prices for this transaction was $18.3000 to $18.3975 per share. This represents the sale of 14,888 shares sold by MDV as nominee for MDV ENF VII(A), L.P. and the sale of 7,752 shares sold by MDV as nominee for MDV ENF VII(B), L.P. The Reporting Persons undertake to provide, upon request by the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. ( 5 )Represents a pro-rata in-kind distribution to the Feiber-Buhr Family Trust, of which Jonathan Feiber and his wife are the sole trustees, from MDV as nominee for MDV VII Leaders Fund, L.P. without consideration. ( 6 )Shares directly held by the Feiber-Buhr Family Trust, of which Jonathan Feiber and his wife are the sole trustees.

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