path: root/_tils/2020-09-04-send-emails-using-the-command-line-for-fun-and-profit.md

---
title: Send emails using the command line for fun and profit!
date: 2020-09-04
layout: post
lang: en
ref: send-emails-using-the-command-line-for-fun-and-profit
---
Here are a few reasons why:

1. send yourself and other people notification of cronjobs, scripts runs, CI
   jobs, *etc.*

2. leverage the POSIX pipe `|`, and pipe emails away!

3. because you can.

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

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

```shell
# 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
```

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

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

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

```shell
# 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
```

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

...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!

[ssmtp]: https://wiki.archlinux.org/index.php/SSMTP
[gnu-mailutils]: https://mailutils.org/
[forwarding-wiki-section]: https://wiki.archlinux.org/index.php/SSMTP#Forward_to_a_Gmail_mail_server