Applies to HMS Version: 2.1+
The following should be considered before using this feature:
- Messages rejected by Mail From Whitelisting are rejected during the initial SMTP protocol exchange, so the messages are not even received by the HMS before being rejected.
- MAIL FROM addresses are not authenticated, and thus can be easily spoofed.
Do not rely on Mail From Whitelisting as the sole method of restricting access to any MTA account!
This feature is enabled and configured by adding a single line to the [RESTRICTIONS] section of the GENERAL.CONFIG file found in an individual account's config directory. Please remember to reload the target account's configuration after making these changes in order for those changes to take effect.
- FIELD: AllowedFromList
- DESCRIPTION: A comma delimited list of email addresses. If set to anything other than an empty string this account will only accept email with a MAIL FROM address that is on this list. The comparison is a case insensitive string in string, allowing matches against substrings and domains.
- EXAMPLE: The following example shows how to create a Mail From Whitelist.
Using the above configuration, only messages that identify themselves as being from any address at @example.com or email@example.com in the MAIL FROM component of the SMTP protocol are accepted by the MTA.
For more information about writing regular expressions, we recommend
third-party resources such as the following:
- http://www.regular-expressions.info/quickstart.html - An introduction to regular expressions
- http://www.regular-expressions.info/reference.html - A quick reference to core regular expression syntax
- http://regexpal.com/ - An online regular expression tester. Highlights test data that matches a regular expression
The following Knowledge Base articles may also be of interest: