Shahriar Rafimayeri - Oct 1, 2021 Form 4 Insider Report for Mimecast Ltd (MIME)

Role: Chief Information Officer
Signature: /s/ Robert P. Nault, Attorney-in-Fact
Stock symbol: MIME
Transactions as of: Oct 1, 2021
Transactions value $: -$165,122
Form type: 4
Date filed: 10/4/2021, 05:30 PM
Next filing: Apr 4, 2022

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MIME	Ordinary Shares	Options Exercise		+4.09K	+884.42%		4.55K	Oct 1, 2021	Direct	F1, F2, F3
transaction	MIME	Restricted Share Units	Tax liability	-$165K	-2.54K	-9.58%	$65.06	24K	Oct 1, 2021	Direct	F2, F4, F5, F6
transaction	MIME	Restricted Share Units	Options Exercise		-4.09K	-17.05%		19.9K	Oct 1, 2021	Direct	F2, F6, F7
holding	MIME	Restricted Share Units						10.4K	Oct 1, 2021	Direct	F2, F8

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The number of Ordinary Shares reflects the settlement of restricted share units upon vesting, net of Ordinary Shares that were retained (but not issued) by the Issuer in satisfaction of tax withholding obligations associated with the vesting of such units.
F2	Each restricted share unit represents a contingent right to receive one share of the Issuer's Ordinary Shares.
F3	Includes 462 Ordinary Shares issued to the Reporting Person on June 30, 2021, under the Mimecast Limited 2015 Employee Share Purchase Plan.
F4	The restricted share units reported as disposed of herein reflect the number of Ordinary Shares underlying the restricted share units that were retained (but not issued) by the Issuer in satisfaction of tax withholding obligations associated with the vesting of such units.
F5	Price reflects the closing price of the Issuer's Ordinary Shares on the Nasdaq Global Select Market on October 1, 2021.
F6	These restricted share units were granted on October 1, 2020. Twenty-five percent (25%) of the units vested on October 1, 2021 and the remainder of the units vest on an annual basis over the next three (3) years, provided that the Reporting Person remains an employee of the Issuer on each such vesting date.
F7	The restricted share units reported as disposed of herein were settled for the Issuer's Ordinary Shares upon the vesting of such units (as reported in Row 1 above).
F8	These restricted share units were granted on April 1, 2021. Twenty-five percent (25%) of the units vest on April 1, 2022 and the remainder of the units vest on an annual basis over the next three (3) years, provided that the Reporting Person remains an employee of the Issuer on each such vesting date.

Remarks:

Exhibit 24 Power of Attorney (incorporated by reference to Power of Attorney filed as Exhibit 24 to Form 3 filed by the Reporting Person on September 2, 2020).