Filter Incoming Emails by Domain

Valid for versions 84 through the latest version



Last modified: July 28, 2022


Use this interface to specify certain domains. Your server will block email messages from those domains. Your server rejects email messages when the From address matches a blocked domain.

This feature is useful, for example, to block all email messages from a domain that sends only spam.

The server uses Filter Incoming Emails by Domain and Filter Incoming Emails by Country filters before it uses any other filters or settings on your system to process email.

Blocked Domains

To block a domain, perform the following steps:

  1. Enter a domain in the Blocked Domains text box.

    • For multiple domains, use a new line for each domain.
    • To view an Internationalized Domain Name (IDN) as ASCII characters, select the Show domains as ASCII (relevant for IDNs) checkbox.

  2. Click Save.

Wildcard characters

To reject all subdomains of a given domain, prefix the domain name with an asterisk (*) character. The asterisk represents a wildcard character. For example, if you were to enter the * domain. Your server will reject any email message from any subdomain of the domain.

Internationalized Domain Name

You can also enter an IDN. This interface converts an IDN into Punycode. Punycode uses multiple ASCII characters to represent a single Unicode IDN character. For example, Punycode would represent the IDN 스타벅스코리아.com domain as the domain.

Additional Documentation