Postfix - need to duplicate mail to external email

Question

I have all the mail coming in from one domain @externaldomain1.com to one mailbox user@mydomain.com, on my mail server (Postfix). I need it to be duplicated to an external mailbox user@externaldomain2.com (at least locally).

Please tell me, which way to dig?

Answer 1

The question is a bit vague, but near as I can tell, you are receiving mail from "outsideuser@someotherdomain.com" to "localuser@yourdomain.com" and what to carbon-copy all inbound email to "differentuser@youcantseethisdomain.com".

Easiest solution is to put an alias in front of the receiving address, then specify both the local address and the remote address in the alias. The entry will look something like this (but not exactly):

localuser: localuser, differentuser@youcantseethisdomain.com

Place the entry in the /etc/aliases file, then run newaliases.

Answer 2

You can try sender_bcc_maps:

http://www.postfix.org/postconf.5.html#sender_bcc_maps

Create file /etc/postfix/sender_bcc with contents:

@externaldomain1.com    user@externaldomain2.com

add to main.cf:

sender_bcc_maps = /etc/postfix/sender_bcc

run:

postmap /etc/postfix/sender_bcc
postfix reload

After that all incoming mails from externaldomain1.com will be copied (bcc) to address user@externaldomain2.com