Hello, I want to enable double delivery for selected users into my MX servers. My MX servers (I have two, load balanced through a Cisco ACE) are only relay servers, once filtered and accepted, emails are transported to a gateway that performs, if needed address rewrite, and dispatch. On MX servers, users do not exists. I have:
- a list of relay_domains, - a big relay_recipient_maps (62K lines), - a single transport rule relay_transport = smtp:[mailgw.my.domain] I would like those MX servers to duplicate the entering emails for a handful of users, and send these duplicates to another server. The purpose is to provide those users with a "webmail" interface where they would be able to tag incoming email "spam" or "ham", in order to train the antispam system. I can create a unix account for each user on the training server, with Maildir, IMAP server, and webmail interface. That's no big deal. The question is: what is the best way to duplicate incoming emails on both MX servers and deliver them on my training server? It must be foolproof, ie. if the duplicate delivery fails, the primary delivery must work. I would like the duplicated emails to be identical, as much as possible, as the primary delivery email. What would be the best way to do this? I've though about using bcc maps, something like this: user1@domain user1@training.domain user2@domain user2@training.domain but in case of failure on the training server side, the From: address would get an delivery error message, right? Any help greatly appreciated! Patrick
