maddy/docs/reference/table/email_with_domains.md

Email with domain

The table module table.email_with_domain appends one or more domains (allowing 1:N expansion) to the specified value.

table.email_with_domains DOMAIN DOMAIN... { }

It can be used to implement domain-level expansion for aliases if used together with table.chain. Example:

modify {
    replace_rcpt chain {
        step email_local_part
        step email_with_domains example.org example.com
    }
}

This configuration will alias anything@anydomain to anything@example.org and anything@example.com.

It is also useful with authorize_sender to authorize sending using multiple addresses under different domains if non-email usernames are used for authentication:

check.authorize_sender {
   ...
   user_to_email email_with_domain example.org example.com
}

This way, user authenticated as user will be allowed to use user@example.org or user@example.com as a sender address.