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From: Hans C. <fo...@gm...> - 2025-11-09 00:50:46
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I'm in the process of upgrading my ancient local-only little home mail server and was wondering how much it matters if I use smtp or sendmail for local delivery. My system is Fedora 43: fetchmail: 6.5.6 postfix: 3.10.3 alpine: 2.26 Keep reading for details of my setup and why I'm asking. My setup is only used for 2 users, with a few email addresses for each user. The MTA is postfix, configured to listen only on loopback port 25 with a self signed cert. There is no access to this server from the outside. The only things that access the MTA are on the same host: alpine for relaying outbound mail and fetchmail for inbound mail. fetchmail is started/stopped daily for each user via cron and each user has the same basic fetchmailrc: set daemon 900 set logfile log/fetchmail.log defaults timeout 120 fetchall nokeep fetchlimit 50 ssl poll ... poll ... poll ... I'm trying to configure smtpd_sender_restrictions in postfix, mainly so I'll get an immediate failure if I've added a new email address that hasn't been configured in postfix. The problem is, if I add smtp_sender_restrictions in the postfix config (main.cf), then those restrictions apply to all connections; both from alpine and fetchmail. I'm fairly certain there's a way to distinguish this by adding something to master.cf (still figuring that part out), but the key is, there needs to be a way to distinguish between the two. I think if fetchmail uses sendmail instead of smtp, I can use that to setup restrictions based on smtp connections (alpine/outbound) and restrictions based on sendmail connections (fetchmail/inbound). Soooo, back to the original question... on my little local-only server are there any pros/cons I should be aware of if I add a fetchmail mda config line to use sendmail (or whatever the postfix equiv is) instead of the default smtp? An alternative, might be to distinguish the two by the fact that alpine connects to smtp via ipv4 and fetchmail connects via ipv6. Maybe I could use that - although I was considering completely disabling ipv6 since I don't plan to ever use it... at least not locally. Then again, maybe this IS a use for ipv6. Thanks for any advice. |