Jose: First of all, you hit the nail on the head as to what I need. Understanding a problem or question is key to solving or answering it.
Now then ... I'll test relayed/routed mail first via the virtual address file and see how that goes. Meanwhile ... On Tue, 16 Jun 2015 09:40:45 -0400, you wrote: >So... I guess "prod" has the mailboxes, and you want to test " >test.example.com" as a prospect replacement for prod. Yes. However, the mailboxes on prod are all virtual. There's one main administrative account that receives local mail, and half a dozen virtual mailboxes, some of which are handled by Dovecot for remote pickup, and some What prod does is process half a dozen mailing lists, all done with Mailman. That configuration has already been ported over, but possibly--probably--not 100% correctly. That I can deal with. The remainder are all in /etc/postfix/virtual. >you will want to enable all the corresponding "local" delivery in test, and >furthermore it could even start thinking it is "prod" (even though it will >still only respond to its address for "test"). After doing this, you can >configure an account on your mail client to connect to "test", and do most >of the tests there. Yes, that's the idea. As I said, not much done locally except the virtual stuff, which I will test forthwith. >This scenario is pretty common when you are configuring a new system, ... I figured (hoped?) as much. >indeed is possible, and there are several ways of doing it, depending on >the details of what you want to do. You could even setup a test subdomain >in order to do a complete test including external mail sending, and before >promoting to production. That might be a little over the top, but maybe not. >Now, the switchover planning (or "promoting test as prod") is another >history, and can be done by several different means, one of those being >using (or creating and then using) a private network and redirecting >traffic on prod to test system, and then doing the DNS change, effectively >making all traffic that would originally go to prod, go to "test" (that now >would be called prod, but I need a way to distinguish them), ... doing this >would either expose you to some spam going through or require some heavy >usage of advanced routing, so, before doing this it is recommended to have >DNS TTL set to something like 60 seconds or so. After 2 minutes has >passed, all new connections should be going to your new prod, and you >should be able to stop prod. Can be done. A little spam for a little while is not unacceptable in this case. >Oh, but there is more: what about mailboxes? (likely maildirs) that's yet >another point that require planning, and will depend on your mailboxes >format, so, won't start with that right now. There are only four users on the system--me, and three other admins, but they're all virtual mailboxes which Dovecot is handling. In other words, there are no accounts on either prod or test for these admins, they get their mail via IMAP or POP just nicely. The real stuff going on is handled by Mailman, which is used for email list management for half a dozen lists. >Well, I hope this is useful, and if you want more help, please elaborate a >bit more on what you want to do. Not sure how to elaborate.
