On 2/24/2014 10:14 AM, Steffen Kaiser wrote: ...
I mean to add a BCC per user to "user"_backup, like a per user alias or forward.
A message to user A is "split" into a message to user A and A_backup, where the new message to user A is not split again.
If using Postfix, this can be accomplished via two methods.
- /etc/aliases
If using local accounts, create a new mailbox and add it as a 2nd value in the 'name: value, value' definition. See: aliases(5)
- /etc/postfix/virtual
If using a virtual(5) table, simply add a 2nd result (address) to each pattern.
Using aliases(5), the 'X-Original-To:' and 'Delivered-To:' headers remain intact. Using virtual(5), these headers are rewritten to the target address(es). The latter shouldn't be a problem for your use case.
Each such address needs to be added to an access(5) table which will be used with check_recipient_access to reject mail coming in via SMTP. You only want backup mail going into these mailboxes, not spam, not mistyped addresses that may match the mailbox name, etc.
-- Stan