Policies - Wildcards In Policies

This article contains information on using Wildcards in Mimecast Policies to match email domains or addresses, including guidelines for wildcard usage, matching order, and limitations for Address Attributes or Header Display Name configurations.

When creating Policies you can populate the Sender and Recipient fields with multiple options, including Groups, Domains, individual email addresses, etc. If multiple email addresses or domains are to be added, Mimecast recommends using Groups to ease the management of these policies.

There may be occasions when you need to include sub-domains of a particular domain, OR you may not be sure of the complete email address or domain for the sender/recipient. Wildcard entries can contain all sub-domains or complete the address or domain variations in these situations.

Wildcard and Regex entries cannot be used for Address Attributes or Header Display Name option(s) when configuring the Applies From & Applies To categories.

Wildcard Usage Guidelines

There are different variations of how a wildcard can be entered in Policies, including adding a regular expression and multi-level wildcard matches. These can be used to match mailbox, sub-domain, or domain portions of addresses:

Below are the guidelines for implementing a wildcard in a Policy From or To field. The following sections help you by focusing on using wildcards to match in the following two areas:

• • • Email Domain Matches
    • Email Address Matches

Email Domain Matches

Email Domains are matched in the following order:

1. Exact match
2. Multi-level domain match
3. Explicit regular expression match
4. Catch-all domain match.

Exact Matches

Exact Matches can only be made when the Domain(s) are identical.

Match Address	Email Address	Matches
example.com	example.com	Yes
example.com	example2.com	No
one.domain.com	one.domain.com	Yes
one.domain.com	one.domain.org	No

Multi-Level Domain Match

Address Domain matches are supported for the following types:

• • • Multi: "*.example.com" matches "one.example.com," "two.example.com", etc. Likewise, "*.*.domain.com" matches "one.domain.com," "two.newdomain.com," etc.
    • Multi-level Domain Wildcard Suffix: Used to match parent domains. For example, "multi: example.*" matches "example.com," "example.org," etc. Likewise, "one.domain.*" matches "one.domain.com," "one.newdomain.org," etc.
    • Multi-level Domain Wildcard Infix: Used to match same-level domains. For example, "multi: one.*.com" matches "one.example.com," "one.domain.com," etc. Likewise, "one.*.example.com" matches "one.domain.example.com," "two.newdomain.example.com," etc.

•  The multi-level Domain Wildcards cannot be used together, e.g., '*.one.*.com', 'one.*.domain.*', or '*.subdomain.*.domain.*', etc.
• The 'multi:' prefix is required for Domain Matches; if not used, the Catch-all match is used.

Match Address	Email Address	Matches
multi: *.domain.com	one.domain.com	Yes
multi: *.domain.com	two.domain.com	Yes
multi: *.domain.com	one.domain.org	No
multi: one.*.com	one.domain.com	Yes
multi: one.*.com	one.newdomain.com	Yes
multi: one. Domain.*	one.domain.com	Yes
multi: one. Domain.*	one.domain.org	Yes
multi: one. Domain.*	one.newdomain.com	No
multi: one. Domain.*	two.domain.com	No

Regular Expression Matches

Match Address	Email Address	Matches
regex: [a-zA-Z0-9]+.com	example.com	Yes
regex: .*\.domain\.com	one.domain.com	Yes

Catch-All Domain Match

Address Domain matches are supported for the following types:

• • • Catch-all Domain Wildcard Prefix: Used to match all sub-Domains, e.g., '*.example.com' matches  one.domain.example.com, two.domain.example.com, etc.
    • Catch-all Domain Wildcard Suffix: Used to match all parent Domains matching a given sub-domain, e.g., 'mail*' matches mail.example.com, mail.one.domain.example.co.uk, mail.two.domain.com, etc.

Match Address	Email Address	Matches
*.domain.com	one.domain.com	Yes
*.domain.com	two.domain.com	Yes
*.domain.com	one.domain.org	No
one*	one.domain.com	Yes
one*	one.newdomain.com	Yes
one*	one.domain.org	Yes
*.domain.com	one.domain.com	Yes
*.newdomain.com	one.domain.com	No

Email Address Matches

Individual email addresses are matched in the following order:

1. Exact address match
2. Compound address match
3. Address mailbox match
4. Address domain match
5. Explicit regular expression address match
6. Catch-all address match

Exact Address Match

Exact Matches can only be made when the address(es) are identical.

Match Address	Email Address	Matches
[e-mail]	[e-mail]	Yes
[e-mail]	[e-mail]	No
[e-mail]	[e-mail]	Yes
[e-mail]	[e-mail]	No

Compound Address Match

The compound address match could be used when wildcards are required in the mailbox and Domain portions. The match is done by comparing the Address, Policy Mailbox, and Domain portions, respectively, and then combining their results to get the match.

The Multi: prefix is required for Compound Address Matches; if not used, the Catch-all match is used.

Match Address	Email Address	Matches
multi: joe*@*.*.com	[e-mail]	Yes
multi: joe*@subdomain.*.com	[e-mail]	Yes
multi: joe*@subdomain.*.*	[e-mail]	Yes
multi: joe*@*.*.*	[e-mail]	No
multi: joe*@*.domain.*	[e-mail]	No

Address Mailbox Match

• • • Exact Local Match: The address in the mailbox matches exactly.
    • Catch-all Local Wildcard Prefix: '*bloggs' matches any address mailbox ending with 'bloggs,' e.g., joe_bloggs, joe.bloggs, jbloggs, etc.
    • Catch-all Local Wildcard Suffix: 'joe*' matches any address mailbox beginning with "joe," e.g., joe_bloggs, joe.bloggs, joebloggs, etc.

Match Address	Email Address	Matches
jbloggs	jbloggs	Yes
jbloggs	j.bloggs	No
jbloggs*	jbloggsest	Yes
jbloggs*	jbloggsing	Yes
joe*	joe.bloggs	Yes
joe.*	joe bloggs	No
joe.*	joe.bloggs	Yes
*bloggs	joe.bloggs	Yes
*.bloggs	joe.bloggs	Yes
*_bloggs	joe.bloggs	No

Address Domain Match

The multi-level Domain wildcards cannot be used together, e.g., '*.one.*.com', 'one.*.domain.*', or '*.one.*.domain.*', etc. Address Domain matches are supported for the following types in the table below.

The Multi: prefix is required for Address Domain Matches; if not used, the Catch-all match is used.

Type	Match Address	Email Address	Matches
Exact Domain	example.com	example.com	Yes
	example.com	example.org	No
	one.domain.com	one.domain.com	Yes
	one.domain.com	one.domain.org	No
	one.domain.com	two.domain.com	No
Multi-Level Domain	multi: *.domain.com	one.domain.com	Yes
	multi: *.domain.com	two.domain.com	Yes
	multi: *.domain.com	one.domain.org	No
	multi: one.*.com	one.domain.com	Yes
	multi: one.*.com	one.newdomain.com	Yes
	multi: one. Domain.*	one.domain.com	Yes
	multi: one. Domain.*	one.domain.org	Yes
	multi: one. Domain.*	one.newdomain.com	No
	multi: one. Domain.*	two.domain.com	No
Catch-All Domain	*.domain.com	one.domain.com	Yes
	*.domain.com	two.domain.com	Yes
	*.domain.com	one.domain.org	No
	one*	one.domain.com	Yes
	one*	one.newdomain.com	Yes
	one*	one.domain.org	Yes
	one. Domain*	one.domain.com	Yes
	one.newdomain*	one.domain.com	No

Regular Expression Match

The prefix Regex: specifies a regular expression for addresses/Domains.

Match Address	Email Address	Matches
regex: recipient@[a-zA-Z0-9]\.com	[e-mail]	Yes
regex: .*@.*\.domain\.com	[e-mail]	Yes

Catch-All Address Match

Matches the wildcard '*' suffix or prefix. It also matches the wildcard at both the beginning and end.

Match Address	Email Address	Matches
*.com	[e-mail]	Yes
recipient*	[e-mail]	Yes
*[e-mail]	[e-mail]	Yes
*example.com	[e-mail]	Yes
joe*	[e-mail]	Yes
joe.*	[e-mail]	Yes
joe.bloggs*	[e-mail]	Yes
joe.bloggs@domain.*	[e-mail]	Yes
*[e-mail]	[e-mail]	Yes
*one.domain.com	[e-mail]	Yes
*.domain.com	[e-mail]	Yes
*accounts*	[e-mail]	Yes
*finance*	[e-mail]	Yes

See Also...

• • • Policy Basics
    • Mimecast Policy Validity
    • Mimecast Policy Specificity
    • Armed SMTP