Wietse, Thanks so much for your quick and helpful response! It's an honor to talk to you!
So my idea might only work, if I use the LAN IP address (e.g. 10.1.2.3) of the internal mail server as relay_host. If Postfix can't connect to 10.1.2.3, it will probably retry mail relaying for some days, configurable in maximal_queue_lifetime. That would be fine. But it will NOT work, if I use an intranet FQDN (e.g. internalmail.myintranet.corp), which can only be resolved, if the laptop is in the LAN or VPN. Then emails get lost if they arrive while not in the LAN / VPN. Or do you maybe have a different idea / suggestion about how to collect local system emails from laptop clients? > Gesendet: Dienstag, 15. November 2022 um 22:45 Uhr > Von: "Wietse Venema" <wie...@porcupine.org> > An: "Postfix users" <postfix-users@postfix.org> > Betreff: Re: What happens if Postfix can't reach relay_host? - Postfix on > laptops for system messages, with relay_host behind VPN > > r.barc...@habmalnefrage.de: > > This leads to my question: What happens to laptop-locally generated > > / received emails, if their local Postfix can't reach the relay_host > > in the intranet? > > The Postfx SMTP client will retry delivery after a soft error (host > or port not reachable) until the message expires in the queue (by > default, maximal_queue_lifetime = 5d). > > The Postfx SMTP client will NOT retry delivery after a hard error > (host or domain does not exist in DNS, user does not exist on the > remote SMP srever). > > Wietse >
