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.

    • @markstosOPEnglish
      2•7 months ago

      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

      • @vegetaaaaaaaEnglish
        1•7 months ago

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

        # /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

        # /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: [email protected]

        (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

        • @markstosOPEnglish
          2•7 months ago

          In the issue I linked, the msmtp author makes a distinction with changing the envelope recipient, which msmtp can do, with rewriting the email headers like “To”, which msmtp does not do.

          • @vegetaaaaaaaEnglish
            2•7 months ago

            https://github.com/chriswayg/ansible-msmtp-mailer/issues/14 While msmtp has features to alter the envelope sender and recipient, it doesn’t alter the “To:” or “From:” message itself. When the Envelope doesn’t match these details, it can be considered spam

            Oh I didn’t know that, good to know!

            The proposed one-line wrapper looks like a nice solution

    • Mark Stosberg
      1•7 months ago

      @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