How can I automatically forward outgoing emails to a different domain?
As an example, a user sends an email to 1234564@fax.mydomain.com and I want the exact email forwarded outside mydomain.com to 1234564@example.com.
Note There are no accounts on the local Zimbra server under the fax.mydomain.com subdomain and the prefix 123456 will not be constant, e.g. it will change depending on fax recipient's number.
I know that the easy thing would be to have users send the emails directly to the @example.com domain, but I'd rather have them use the local fax.mydomain.com domain and have the email forwarded/ redirected.
I don't know whether to use postfix transports, procmail or something within zimbra.
I think that postfix transports requires that I specify a different SMTP server, e.g. otherdomain.com :[smtp.otherdomain.com]
With procmail I think I would need to use a pipe, but I've never used procmail.
I've tried to find a feature within Zimbra and I tried to zmprov md fax.mydomain.com zimbraMailCatchAllForwardingAddress @example.com
but the emails bounced.
How do I best achieve this?