LIMITED POWER OF ATTORNEY

The undersigned hereby constitutes and appoints Paul Auvil, Michael Yang and
Kyle Chin, as long as they are providing services to Proofpoint, Inc. or its
related entities (the "Company"), or any of them, the undersigned's true and
lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer and/or director of the Company, Forms 3, 4 and 5 in accordance
with Section 16(a) of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), and the rules and regulations thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned that
may be necessary or desirable to complete and execute any such Forms 3, 4 and 5
and timely file such forms with the Securities and Exchange Commission and any
stock exchange or similar authority, if required; and

(3) take any other action of any type whatsoever in connection with the
foregoing that, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and
conditions as such attorney-in-fact may approve in such attorney-in-fact's
discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform each and every act and thing whatsoever requisite,
necessary or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution and revocation,
hereby ratifying and
confirming all that each such attorney-in-fact, or each such attorney-in-fact's
substitute or substitutes, shall lawfully do or cause to be done by virtue of
this power of attorney and the rights and powers herein granted. The undersigned
acknowledges that each of the foregoing attorneys-in-fact, in serving in such
capacity at the request of the undersigned, is not assuming, nor is the Company
assuming, any of the undersigned's responsibilities to comply with Section 16 of
the Exchange Act.

The undersigned agrees that each such attorney-in-fact may rely entirely on
information furnished orally or in writing by the undersigned to each such
attorney-in-fact. The undersigned also agrees to indemnify and hold harmless the
Company and each such attorney-in-fact against any losses, claims, damages or
liabilities (or actions in these respects) that arise out of or are based on any
untrue statement or
omission of necessary facts in the information provided by the undersigned to
such attorney-in-fact for purposes of executing, acknowledging, delivering and
filing Forms 3, 4 or 5 (including amendments thereto) and agrees to reimburse
the Company and each such attorney-in-fact for any legal or other expenses
reasonably incurred in connection with investigating or defending against any
such loss, claim, damage,
liability or action.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 25th day of February, 2021.

/s/ Elizabeth Rafael
Elizabeth Rafael