Walsh John J JR Form 4 Mimecast / JOHN J WALSH JR ownership change

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:	3235-0287
Estimated average burden
hours per response:	0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

WALSH JOHN J JR

(Last) (First) (Middle)

C/O MIMECAST NORTH AMERICA, INC.

191 SPRING STREET

(Street)

LEXINGTON MA 02421

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Mimecast Ltd [ MIME ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
Sr. Vice Pres., Engineering

3. Date of Earliest Transaction (Month/Day/Year)
05/17/2021

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares	05/17/2021		M		2,000	A	$24.45	3,642	D
Ordinary Shares	05/17/2021		S(1)		2,000	D	$47.04	1,642	D
Restricted Share Units(2)								14,687(3)	D
Restricted Share Units(2)								22,469(4)	D
Restricted Share Units(2)								5,500(5)	D
Restricted Share Units(2)								850(6)	D
Restricted Share Units(2)								825(7)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Share Option (Right to Buy)	$24.45	05/17/2021		M			2,000	(8)	05/01/2027	Ordinary Shares	2,000	$0.00	101,500(8)	D

Explanation of Responses:

1. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 12, 2020.

2. Each restricted share unit represents a contingent right to receive one share of the Issuer's Ordinary Shares.

3. 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.

4. These restricted share units were granted on April 1, 2020. Twenty-five percent (25%) of the units vested on April 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.

5. These restricted share units were granted on April 1, 2019. Twenty-five percent (25%) of the units vested on April 1, 2020, twenty-five percent (25%) of the units vested on April 1, 2021, and the remainder of the units vest on an annual basis over the next two (2) years, provided that the Reporting Person remains an employee of the Issuer on each such vesting date.

6. These restricted share units were granted on June 1, 2018. Twenty-five percent (25%) of the units vested on June 1, 2019, twenty-five percent (25%) of the units vested on June 1, 2020, and the remainder of the units vest on an annual basis over the next two (2) years, provided that the Reporting Person remains an employee of the Issuer on each such vesting date.

7. These restricted share units were granted on April 2, 2018. Twenty-five percent (25%) of the units vested on April 2, 2019, twenty-five percent (25%) of the units vested on April 2, 2020, twenty-five percent (25%) of the units vested on April 2, 2021, and the remainder of the units vest on April 2, 2022, provided that the Reporting Person remains an employee of the Issuer on such vesting date.

8. This option was granted on May 1, 2017. Twenty-five percent (25%) of the shares vested on May 1, 2018 and the remainder of the shares vested on a quarterly basis over the next three (3) years. This option is fully vested.

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 April 2, 2018).

	/s/ Robert P. Nault, Attorney-in-Fact	05/17/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.