About Internal Domains

Overview

Internal domains are used to determine whether an email address is internal or external.
During the internal determination, you can also specify excluded addresses that are determined to be external regardless of the internal domain settings.

Internal Domain Attributes

The list of internal domain attributes is as follows.

Item	Description
Scope	Determines the range of users to which the internal domain applies. The following scopes exist. Tenant All users belonging to the tenant. Group All users belonging to a group. User An individual user.
Internal domain name	The domain name used during the internal determination.
Internal domain match type	The match type used during the internal determination. The following internal domain match types exist. Suffix match Determines a domain that suffix-matches the internal domain name as internal. Exact match Determines a domain that exactly matches the internal domain name as internal. Prefix match Determines a domain that prefix-matches the internal domain name as internal.
Description	The description of the internal domain.
Status	The status of the internal domain. The following statuses exist. Enabled Disabled

Excluded Address Attributes

The list of excluded address attributes is as follows.

Item	Description
Scope	Determines the range of users to which the excluded address applies. The following scopes exist. Tenant All users belonging to the tenant. Group All users belonging to a group. User An individual user.
Excluded address	An email address that is determined to be external regardless of the internal domain settings. An asterisk (*) within an excluded address is treated as any string of zero or more characters. An asterisk (*) cannot be set as a literal character.
Description	The description of the excluded address.
Status	The status of the excluded address. The following statuses exist. Enabled Disabled

Internal Determination of Email Addresses

The procedure by which a user determines whether an email address is internal is as follows.

1. List the Tenant internal domains, Group internal domains, and User internal domains linked to the user whose status is Enabled.
2. If the email address matches any of the internal domains listed in step 1, proceed to step 3. If it does not match, it is determined to be external.
   During the match determination, the domain part of the email address is matched against the internal domain's Internal domain name according to the Internal domain match type.
3. List the Tenant excluded addresses, Group excluded addresses, and User excluded addresses linked to the user whose status is Enabled.
4. If the email address matches any of the excluded addresses listed in step 3, it is determined to be external. If it does not match, it is determined to be internal.
   During the match determination, an asterisk (*) within an excluded address is treated as any string of zero or more characters.

Internal domain	Excluded address	Result
〇	×	Internal
〇	〇	External
×	〇	External
×	×	External