systemmail@adomain.se

smtp.gmail.com smtp --port=587 --auth-login --user=systemmail@adomain.se --pass=thepassword--starttls

echo "Test 1" | mailq -s "Test one" john.doe@adomain.se

$ sendmail -v john.doe@adomain.se <<EOM
> Subject: Test mail four
> The message body
>
> EOM

$ cat /var/log/mail.err
Sep  3 14:42:52 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:43:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:44:37  nullmailer[1490]: last message repeated 3 times
Sep  3 14:45:37  nullmailer[1490]: last message repeated 2 times
Sep  3 14:46:37  nullmailer[1490]: last message repeated 2 times
$ cat /var/log/mail.log
Sep  3 14:28:17 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:42:52 cow nullmailer[1490]: Trigger pulled.
Sep  3 14:42:52 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:42:52 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:42:52 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:42:52 cow nullmailer[1490]: Delivery complete, 1 message(s) remain.
Sep  3 14:43:29 cow nullmailer[1490]: Trigger pulled.
Sep  3 14:43:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:43:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:43:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:43:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:43:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:43:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:44:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:44:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:44:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:44:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:44:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:44:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:45:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:45:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:45:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:45:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:45:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:45:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:46:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:46:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:46:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:46:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:46:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:46:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
$ grep nullmailer /var/log/syslog
Sep  3 14:28:17 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:42:52 cow nullmailer[1490]: Trigger pulled.
Sep  3 14:42:52 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:42:52 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:42:52 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:42:52 cow nullmailer[1490]: Delivery complete, 1 message(s) remain.
Sep  3 14:43:29 cow nullmailer[1490]: Trigger pulled.
Sep  3 14:43:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:43:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:43:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:43:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:43:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:43:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:44:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:44:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:44:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:44:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:44:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:44:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:45:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:45:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:45:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:45:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:45:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:45:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:46:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:46:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:46:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:46:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:46:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:46:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.
Sep  3 14:47:29 cow nullmailer[1490]: Rescanning queue.
Sep  3 14:47:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212209.2284
Sep  3 14:47:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:47:29 cow nullmailer[1490]: Starting delivery: protocol: smtp host: smtp.gmail.com file: 1378212171.2280
Sep  3 14:47:29 cow nullmailer[1490]: Sending failed:  Unspecified temporary error
Sep  3 14:47:29 cow nullmailer[1490]: Delivery complete, 2 message(s) remain.

$ ls /var/spool/nullmailer/queue/
1378212171.2280  1378212209.2284
$ ls /var/spool/nullmailer/tmp/
31464  31468  31672

sudo apt-add-repository ppa:mikko-red-innovation/ppa
sudo apt-get update
sudo apt-get install nullmailer=1:1.11-2~precise1~ppa1

root# /usr/lib/nullmailer/smtp -h
usage: smtp [flags] remote-address < mail-file
Send an email message via SMTP
  -p, --port=INT    Set the port number on the remote host to connect to
      --user=VALUE  Set the user name for authentication
      --pass=VALUE  Set the password for authentication
  -d, --daemon      use syslog exclusively
  -s, --syslog      use syslog additionally
      --auth-login  Use AUTH LOGIN instead of AUTH PLAIN in SMTP

  -h, --help        Display this help and exit