What are domain aliases in SpamExperts?
You can configure an unlimited number of domain aliases for a domain filter. All email traffic sent to any of those configured domain aliases will also be filtered, but all legal emails will be forwarded to the email user on the main domain.
You configured the filter for example.com, using mail server mail.example.com
For this domain, you add otherdomain.com as an alias
An email sent to email@example.com will be examined by SpamExperts filter and delivered to firstname.lastname@example.org
The To field in the email header will show the original e-mail address