MIME 2018 Proxy Statement

Equity Compensation Plans In accordance with SEC rules, the following table provides information, as of March 31, 2018, about the securities authorized for issuance under our equity compensation plans. Equity Compensation Plan Information Plan Category Number of Shares to be Issued upon Exercise of Outstanding Options and Rights (Column A) Weighted Average Exercise Price of Outstanding Options (Column B) Number of Shares Remaining Available for Future Issuance under Equity Compensation Plans (Excluding Shares Reflected in Column A) (Column C) Equity compensation plans that have been approved by our shareholders . . . . . . . . . . . . . . . . . . . 6,262,623 (1) $13.78 (2) 9,797,615 (3) Equity compensation plans that have not been approved by our shareholders . . . . . . . . . . . . . . . . . . . — — — Total . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,262,623 (1) $13.78 (2) 9,797,615 (3) (1) Represents 6,229,860 ordinary shares to be issued upon exercise of outstanding share options under the Mimecast Limited 2007 Key Employee Share Option Plan, the Mimecast Limited 2010 EMI Share Option Scheme, the Mimecast Limited Approved Share Option Plan, and the Mimecast Limited 2015 Share Option and Incentive Plan. Also includes 32,763 ordinary shares to be issued upon settlement of outstanding restricted share units under the Mimecast Limited 2015 Share Option and Incentive Plan. We no longer grant equity awards under the Mimecast Limited 2007 Key Employee Share Option Plan, the Mimecast Limited 2010 EMI Share Option Scheme, or the Mimecast Limited Approved Share Option Plan. (2) Weighted average exercise price excludes restricted share units, which do not have an exercise price. (3) Includes 8,761,886 ordinary shares available for issuance under the Mimecast Limited 2015 Share Option and Incentive Plan. Also includes 1,035,729 ordinary shares available for issuance under the Mimecast Limited 2015 Employee Share Purchase Plan. REPORT OF THE COMPENSATION COMMITTEE OF THE BOARD OF DIRECTORS The compensation committee has reviewed and discussed the Compensation Discussion and Analysis required by Item 402(b) of Regulation S-K with management, and, based on such review and discussions, the compensation committee recommended to the Board that the Compensation Discussion and Analysis be included in this Proxy Statement, which will be incorporated by reference into our Annual Report on Form 10-K for the year ended March 31, 2018. Compensation Committee Jeffrey Lieberman, Chairman Aron Ain Christopher FitzGerald 43