Skip Navigation
selfhosted Selfhosted @lemmy.world
markstos @lemmy.world

Recommendation for outgoing-only SMTP server

I'm looking for a simple sendmail replacement to receive local mail, such as from cron and service failures and forward it to on to a real SMTP server.

I have used msmtpd successfully but thought I'd ask if folks have other solutions they like.

34 comments

  • msmtp never failed me

    • The one problem with msmtp is that it doesn't rewrite headers, like "From: root / To: root". These are not required for SMTP, but they are required by some mail providers who will reject email that doesn't have an "@" sign in these headers. The author or msmtp has said he does not plan to add this feature.

      I worked around the issue with my own sendmail wrapper that rewrites local addresses in From and To headers before passing the message to msmtp. Someone else posted such a script in this bug report:

      https://github.com/marlam/msmtp/issues/98

      • You can definitely replace senders with correct mail addresses for relaying through SMTP servers that expect them (this is what I do):

         bash
            
# /etc/msmtprc
account default
...
host smtp.gmail.com
auto_from on
auth on
user myaddress
password hunter2

# Replace local recipients with addresses in the aliases file
aliases /etc/aliases

  
         bash
            
# /etc/aliases
mailer-daemon: postmaster
postmaster: root
nobody: root
hostmaster: root
usenet: root
news: root
webmaster: root
www: root
ftp: root
abuse: root
noc: root
security: root
root: default
www-data: root
default: myaddress@gmail.com

        (the only thing I changed from the defaults in the aliases file is adding the last line)

        This makes it so all/most system accounts susceptible to send mail are aliased to root, and root in turn is aliased to my email address (which is the one configured in host/user/password in msmtprc)

        Edit: I think it's actually the auto_from option which interests you. Check the msmtp manpage

    • @vegetaaaaaaa

      After testing ssmtp, nullmailer, and msmtp for relay-only outgoing mail on Fedora #Linux. Here's my final report:

      ssmtp is packaged for Fedora and I got it working, but the Ansible role I found for it had been abandoned by the author because ssmtp itself is unmaintained.
      nullmailer might have worked, but is not packaged for Fedora.
      msmtp worked. I used this Ansible role, after patching it to work on Fedora: https://github.com/chriswayg/ansible-msmtp-mailer

  • It has been a while since I touched ssmtp, so take what I'm saying with a grain of salt.

    Problem with ssmtp and related when I was testing it was its behaviour in error conditions - due to a lack of any kind of spool it doesn't fail very gracefully, and if the sending software doesn't expect it and implement a spool itself (which it typically doesn't have a reason to, as pretty much the only situation where something like sendmail would fail is a situation where it also wouldn't be able to write a spool) this can very easily lead to loss of mails.

    I already had a working SMTP client capable of fishing mails out of a Maildir at that point, so I ended up just doing a simple sendmail program throwing whatever it receives into a Maildir, and a cronjob to send this forward. This might be the most minimalistic setup for reliably sending out mail (and I'm using it an all my computers behind Emacs to do so) - but it is badly documented, so if you don't care about reliability postfix might be a better choice, or if you don't just go with ssmtp or similar. Or if you do want to dig into that message me, and I'll help making things more user friendly.

34 comments