On 2019-06-09 13:42, Ronald F. Guilmette wrote:
I'd very much like to move my (Postfix) mail server, which currently resides on a (static IP) end-luser broadband line, to some VM in the cloud someplace, and then use something like fetchmail to poll that periodically to pull down all mail for my several domains and then have fetchmail re-inject all of those mail messages into the local Postfix. The plan would be to get all this running and then give up my local static IP here, exchanging it for a dynamic one instead. (This will save me a tiny bit of money on my monthy local ISP bill.)Googling for options just now, it sure sounds like ODMR/ATRN would fit my needs nicely, however I can't quite make out whether any of this ODMR/ATRN stuff has ever actually been implemented in Postfix or not. Has it been? Regardless of whether it has or not, if anyone wants to suggest or recommend any alternative solution(s) I'm all ears. I am open to anything that will get the job done. My only real requirements for a solution are: 1) Must support unlimited email addresses per each recipient domain. 2) Must preserve envelope sender information.
I use authenticated SMTP for this. Each cloud VM has two postfix instances: One is the MX: - low-security opportunistic TLS - spam filtering - envelop validation using relay_domains and relay_recipient_maps The other is the authenticated SMTP relay: - mandatory TLSv1.3 with private EC PKI - permit_tls_clientcerts only - soft_bounce=yes - long maximal_queue_lifetime - per-destination transports for defer_transports granularity
