MIME 2018 Proxy Statement

MIMECAST LIMITED City Point, One Ropemaker Street, Moorgate London EC2Y 9AW United Kingdom NOTICE OF 2018 ANNUAL GENERAL MEETING OF MIMECAST LIMITED Notice is hereby given that Mimecast Limited (“Mimecast” or the “Company”), will hold its 2018 Annual General Meeting (the “Annual Meeting”) on Thursday, October 4, 2018, at 10:00 a.m. (London time), at Mimecast’s offices located at City Point, One Ropemaker Street, Moorgate, London EC2Y 9AW, United Kingdom, for the purpose of passing the following resolutions: ORDINARY RESOLUTIONS Re-election of Directors 1. To re-elect Peter Bauer as a Class III director of the Company to hold office until the 2021 annual general meeting and until his successor is duly elected and qualified, subject to his earlier resignation or removal; 2. To re-elect Jeffrey Lieberman as a Class III director of the Company to hold office until the 2021 annual general meeting and until his successor is duly elected and qualified, subject to his earlier resignation or removal; and 3. To re-elect Hagi Schwartz as a Class III director of the Company to hold office until the 2021 annual general meeting and until his successor is duly elected and qualified, subject to his earlier resignation or removal. Auditors 4. To appoint Ernst & Young LLP in the United Kingdom as our independent auditors for the year commencing on the conclusion of the Annual Meeting until the conclusion of the annual general meeting to be held in 2019; and 5. To authorise the Board of Directors of the Company to determine the remuneration of the auditors. ADVISORY, NON-BINDING ORDINARY RESOLUTIONS 6. To receive the Company’s accounts for the year ended March 31, 2018 together with the directors’ report and the auditors’ report on those accounts; and 7. To approve the compensation of the Company’s named executive officers, as disclosed in this Proxy Statement pursuant to Item 402 of Regulation S-K, including in the Compensation Discussion and Analysis, the compensation tables and the narrative disclosures that accompany the compensation tables. ADVISORY, NON-BINDING PLURALITY RESOLUTION 8. To approve the submission by the Company of a non-binding, advisory say-on-pay resolution pursuant to Section 14A of the Securities Exchange Act of 1934, as amended, every: — one year — two years; or — three years. Only shareholders of record as of 4:00 p.m. (London time) on October 2, 2018 are entitled to vote at the Annual Meeting as set forth in the Proxy Statement. If you plan to attend the Annual Meeting in person, you should be prepared to present photo identification such as a valid driver’s license or passport and verification of share ownership