Problem

How to send emails with msmtp cli using outMail?

Solution

Follow the guide below to send emails using the command line tool msmtp for linux. More detailed information on msmtp usage and parameters can be found at marlam.de/msmtp ^{[Disclaimer - 3rd party link]}

This article already assumes your Linux system is working, has suitable Internet access, and you have the necessary permissions to run applications at the shell prompt.  It is also assumed you have installed the msmtp application or you have built it from the source github.com/marlam/msmtp ^{[Disclaimer - 3rd party link]}.

Although this KB article has been written using linux as the OS, msmtp works with Linux, MacOS and WSL (Windows Subsystem for Linux).  The guide below can easily be adapted for those operating systems.

You will also need your outMail SMTP credentials.

Method 1

msmtp is a command line tool and for this example we are going to use the following command line switches

The example command line will look like the below

printf "To: fred@example.com\nFrom: me@example.com\nSubject: My Subject line...\n\nThe body of the message...\n" | \
msmtp --host=mxXXXXXX.smtp-engine.com \
      --port=8025 \
      --auth=login \
      --user="outmail-username" \
      --passwordeval='echo outmail-password' \
      --from=me@example.com \
      --domain=example.com \
      --tls=on \
      --tls-certcheck=off \
      --logfile=/tmp/msmtp.log \
      fred@example.com

To check the result of the email send please check the log file, in this example its C:\SwithMail\log.txt.

Example of the log is below

MMM DD HH:MM:SS host=mxXXXXXX.smtp-engine.com tls=on auth=on user=outmail-username from=me@example.com recipients=fred@example.com mailsize=234 smtpstatus=250 smtpmsg='250 2.0.0 Ok: queued as ABC456789' exitcode=EX_OK

Method 2

The second solution is rather than specifying all the parameters on the command line you can save the settings in a profile file to use.

Let's create a profile (Note: in msmtp it's called an account) called "outmail"

Create/Edit a file called ~/.msmtprc

defaults
auth           on
tls            on
tls_certcheck  off
logfile        /tmp/msmtp.log

account        outmail
host           mxXXXXXX.smtp-engine.com
port           2525
from           me@example.com
user           outmail-username
password       outmail-password

account default : outmail

The msmtp command line tool will now be used with the settings in the msmtprc file and the following command line switches

The example command line will look like the below

printf "To: fred@example.com\nFrom: me@example.com\nSubject: My Subject line...\n\nThe body of the message...\n" | \
msmtp --account=outmail \
      fred@example.com

To check the result of the email send please check the log file, in this example its /tmp/msmtplog.

Example of the log is below

MMM DD HH:MM:SS host=mxXXXXXX.smtp-engine.com tls=on auth=on user=outmail-username from=me@example.com recipients=fred@example.com mailsize=230 smtpstatus=250 smtpmsg='250 2.0.0 Ok: queued as ABC456791' exitcode=EX_OK

Sending emails with msmtp using a shell script

The example below shows how to send emails using msmtp with outMail as the SMTP relay host in a bash shell script.

create a file called demo-msmtp-with-outmail.sh

#!/bin/bash

# Email details
TO="fred@example.com"
FROM="me@example.com"
SUBJECT="My Subject line"
BODY="The body of the message"
SMTP_SERVER="mxXXXXXX.smtp-engine.com"
SMTP_PORT="2525"
SMTP_USER="outmail-username"
SMTP_PASS="outmail-password"

# Construct the email content
EMAIL_CONTENT="To: ${TO}
From: ${FROM}
Subject: ${SUBJECT}

${BODY}"

# Send the email using msmtp
printf "${EMAIL_CONTENT}" | msmtp \
  --host="${SMTP_SERVER}" \
  --port="${SMTP_PORT}" \
  --auth=plain \
  --user="${SMTP_USER}" \
  --passwordeval="echo ${SMTP_PASS}" \
  --from="${FROM}" \
  --tls=on \
  --tls-certcheck=off \
  "${TO}"

Problem Solving

Below is a list of common gotchas.

Relay access denied

You need to check you're passing the correct parameters.  Remember outMail is a SMTP authenticated service. Double check your outMail SMTP credentials (username and password). Both are case sensitive.