#ssmtp

# apt install msmtp

/etc/msmtprc:

defaults port 587 tls on tls_trust_file /etc/ssl/certs/ca-certificates.crt

account <account-name> host smtp.example.org from <your-email> auth on user <your-username> password <your-password>

account default : <account-name>

Es gib immer mal wieder die Situation mit einem Linux System E-Mails zu versenden. Das können zu hohe Temperaturen der Festplatte, störungen von Cronjob oder eine IP, die aufgrund von falschen Login versuchen auffällt. Natürlich ist dieser Service auch bei anderen Diensten wie FHEM interessant.  Man könnte sich eine E-Mail senden lassen wenn ein bestimmter Bewegungsmelder aktiv wird.  Oder die Temperatur der Gefriertruhe steigt wegen einem defekt. Hier kann auch sSMTP einspringen und eine E-Mail versenden. Die Einsatzmöglichkeiten sind unglaublich vielfältig. Und diese Möglichkeiten gibt es mit sSMTP mit relativ wenig Aufwand.

Installation von sSMTP

L'installation et La configuration de SSMTP vous prendront quelques minutes à peine pour disposer d'un serveur d'envoi adapté à vos applications Web.

How I test that ssmtp is configured properly

I recently upgraded our Rails 2.x application (barrelrun.com) to Rails 3.1.  It went pretty well and everything worked smoothly on my local development instance however, when I deployed to our EngineYard servers I kept having problems with Action Mailer.  Every time an email was being send from the application (we use Devise and we send confirmation emails on registration) we would see the following error:

Errno::EPIPE: Broken pipe

and then a stack dump pointing to some issue in the mailer.  Unfortunately the above error was pretty useless to me, I didn't even know how to debug it.  Turns out though that this error gets raised because there is an issue with the actual linux mail command that gets executed (by rails).  You can actually see this if you try to run the mail from the rails console:

irb> User.find(1).send_confirmation_instructions

This would raise the same error as from the actual rails application (which makes sense) with the exception of the following nugget:

"sendmail: recipients with -t option not supported"

This finally got me on the right track to debug the issue.  I tried to send email from the command line, not using Rails at all:

> sendmail -t [email protected]

sendmail: recipients with -t option not supported

And presto, that same error message comes up.  As it turns out, on EngineYard, sendmail is symlinked to ssmpt and ssmtp raises an error when you supply an email with the -t option.  -t is used to indicate that the recipients will be specified in the message itself (prefixed by either 'To:', 'cc:' or 'bcc:') and therefore there is no point in specifying the recipients on the actual command line.  However, the actual sendmail command will just ignore -t in that case but it seems that ssmtp raises an error.  

It seems that Rails IS providing the email address as part of the command line and therefore ssmtp raises an error and Rails barfs. The solution is as simple as overwriting the default arguments provided by the mail gem. You do this in your environment files, e.g. in config/environments/development.rb:

config.action_mailer.sendmail_settings = {  :arguments => '-i'  }

Sending emails started working after I added this.