Send emails using the command line for fun and profit!

Here are a few reasons why:

send yourself and other people notification of cronjobs, scripts runs, CI jobs, etc.
leverage the POSIX pipe |, and pipe emails away!
because you can.

Reason 3 is the fun part, reasons 1 and 2 are the profit part.

First install and configure SSMTP for using, say, Gmail as the email server:

# file /etc/ssmtp/ssmtp.conf
FromLineOverride=YES
MailHub=smtp.gmail.com:587
UseSTARTTLS=YES
UseTLS=YES
rewriteDomain=gmail.com
root=username@gmail.com
AuthUser=username
AuthPass=password

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Now install GNU Mailutils (sudo apt-get install mailutils or the equivalent on your OS), and send yourself your first email:

echo body | mail -aFrom:email@example.com email@example.com -s subject

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And that’s about it, you’ve got mail. Here are some more places where it might be applicable:

# report a backup cronjob, attaching logs
set -e

finish() {
  status=$?
  if [[ $status = 0 ]]; then
    STATUS="SUCCESS (status $status)"
  else
    STATUS="FAILURE (status $status)"
  fi

  mail user@example.com                                 \
       -s "Backup job report on $(hostname): ${STATUS}" \
       --content-type 'text/plain; charset=utf-8'       \
       -A"$LOG_FILE" <<< 'The log report is in the attachment.'
}
trap finish EXIT

do-long-backup-cmd-here

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1
2 # share the output of a cmd with someone
some-program | mail someone@example.com -s "The weird logs that I was talking about"

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…and so on.

You may consider adding a alias mail='mail -aFrom:email@example.com' so you don’t keep re-entering the “From: “ part.

Send yourself some emails to see it working!