UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

Form 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):  November 7, 2017

Proofpoint, Inc.

(Exact name of registrant as specified in its charter)

(408) 517-4710

(Registrant’s telephone number, including area code)

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o                 Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o                 Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o                 Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o                 Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company   o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.   o

Item 7.01                   Regulation FD Disclosure.

On November 7, 2017 Proofpoint, Inc. (“Proofpoint”) issued a press release announcing it had entered into a definitive agreement to acquire Cloudmark, Inc.  In connection with that press release Proofpoint announced that, contingent upon the closing of such acquisition, for the full year 2018 Proofpoint was increasing its expected total revenue range forecast by $20 to $25 million to $664 million to $673 million and increasing its expected billings range forecast by $20 to $25 million to $818 million to $827 million.  Proofpoint’s policy is not to reiterate or adjust financial guidance unless it is also done through a public disclosure such as a press release or Form 8-K.

The information in this Current Report on Form 8-K and Exhibit 99.1 attached hereto (the “7.01 Information”) is being furnished pursuant to Item 7.01 of Form 8-K and will not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor will the 7.01 Information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such filing.

Item 9.01                Financial Statements and Exhibits.

(d)                                 Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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