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•9 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•9 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•9 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•9 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