On 10/03/2020 21:11, Robert Blayzor via Exim-users wrote: > I'm looking to setup several Exim MX VM servers to deliver mail to > mailbox storage in Maildir++ on FreeNAS. > > Will be using Dovecot for the IMAP/POP and LMTP delivery. My main goal > is to keep the MX's accepting mail should for whatever reason the NAS > appliance go offline. > > That would mean that direct NFS mounts are out. (or is it?)
Depends where the LMTP server is. > I was kicking around running Dovecot LMTP/LDA on a jail directly on in a > NAS jail (freeNAS) and then just use SMTP/LMTP transport from the MX > servers to the LMTP server running in the NAS jail. This way if for some > reason the NAS goes down; SMTP protocol would just time out or fail and > the MX server would queue/retry delivery later. Yup, with the LMTP server on the NAS, that works. If the NAS goes down then accepted stuff just builds up in the MX spools. > Would this be a valid design and what are the caveats? What would a > better design option be? I assume you said "multiple" MXs so that you can run system-upgrades and planned-maint on them separately, without taking a mail-acceptance outage. I'd suggest, given you're wanting that service level, you might also want geographically-separate secondary-MX systems for backhoe-induced outage and DDOS protection. I guess another possible reason would be running processing-intensive antispam scanning. SpamAssassin used to be notorious for eating cycles, but I don't know if that still holds on modern hardware. I don't use it myself. > One caveat I have run into is that we will have multiple NAS appliances > holding mailboxes across multiple domains. This raises the issue of the > Exim router looking at the mailbox user and knowing which NAS/LMTP > server to deliver the mail to. This may be something as simple as > putting a value along with the user in the database.... That's the simplest solution, yes. -- Cheers, Jeremy -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
