Sending emails using Gmail and msmtp on Ubuntu / Debian

setup-msmtp-for-gmail.sh

#!/bin/sh
# Sending emails using Gmail and msmtp on ubuntu 18.04
# Author: [Nuno Sarmento](https://www.nuno-sarmento.com)
# Git: [Git](https://github.com/nfsarmento)
# Usage: chmod +x setup-msmtp-for-gmail.sh && ./setup-msmtp-for-gmail.sh
# You should enable "Less secure app access" under gmail/account/security.

sudo apt-get update -q
sudo apt-get install msmtp
sudo apt-get install msmtp-mta ca-certificates heirloom-mailx -yq

if command -v zenity >/dev/null; then
  GMAIL_USER=$(zenity --entry --title="Gmail username" --text="Enter your gmail username with domain (username@gmail.com):")
  GMAIL_PASS=$(zenity --entry --title="Gmail password" --text="Enter your gmail password:" --hide-text)
else
  read -p "Gmail username with domain (username@gmail.com): " GMAIL_USER
  read -p "Gmail password: " GMAIL_PASS
fi
 
echo # an empty line
 
if [ -z "$GMAIL_USER" ]; then echo "No gmail username given. Exiting."; exit -1; fi
if [ -z "$GMAIL_PASS" ]; then echo "No gmail password given. Exiting."; exit -1; fi

sudo tee /etc/msmtprc >/dev/null <<__EOF

# Accounts will inherit settings from this section
defaults
auth            on
tls             on
tls_certcheck   off

# tls_trust_file  /etc/ssl/certs/ca-certificates.crt
logfile /var/log/msmtp.log

# A first gmail address
account   gmail
host      smtp.gmail.com
port      587
from      $GMAIL_USER
user      $GMAIL_USER
password  $GMAIL_PASS

# Set a default account
account default : gmail
__EOF

sudo chmod 600 /etc/msmtprc
sudo chown -R www-data:www-data /etc/msmtprc

HOST=$(hostname)

sudo mail -vs "Email relaying configured at ${HOST}" $GMAIL_USER <<__EOF
The postfix service has been configured at host '${HOST}'.
Thank you for using this postfix configuration script.
__EOF
 
echo "I have sent you a mail to $GMAIL_USER"
echo "This will confirm that the configuration is good."
echo "Please check your inbox at gmail."