Zabbix email alert script with TLS support

zext_msmtp.sh

#! /bin/sh
################################################################################
# Zabbix extensions (C) 2011-* Joseph Bueno <[email protected]>
# Published under GNU General Public License version 2 or later.
# See LICENSE.txt
#-------------------------------------------------------------------------------
# Usage:
#   zext_msmtp.sh <recipient> <subject> <message>
#
# Description:
#  Uses msmtp to send an email. 
#  This script inserts headers:
#    From:    see FROM variable
#    To:      using <recipient>
#    Date:    dynamically computed
#    Subject: using <subject>
#
#  <message> may start with headers, msmtp will seperate them from message body
#  and put them in message headers section.
#
# It uses an msmtp account as defined in MSMTP_ACCOUNT
# Account is defined in /etc/msmtprc
#  
# simple account configuration
# ----------------------------
# account zabbix
# host smtp.example.org
# from [email protected]
#
# advanced account setup (authentication + TLS on Gmail)
# ------------------------------------------------------
# account zabbix
# tls on
# tls_starttls on
# tls_trust_file /etc/ssl/certs/ca-certificates.crt
# host smtp.gmail.com
# port 587
# auth on
# from [email protected]
# user [email protected]
# password ***********
# 
# (from, user and password should be replaced with real values).
#
# Dependencies
#  It needs msmtp utility
#  On Debian and Ubuntu:
#    apt-get install msmtp
#
################################################################################
DEBUG=0
if [ $DEBUG -gt 0 ]
then
	exec 2>>/tmp/zext_msmtp.log
	set -x
fi
# Default parameters
FROM='[email protected]'
MSMTP_ACCOUNT='zabbix'

# Parameters (as passed by Zabbix):
#  $1 : Recipient 
#  $2 : Subject
#  $3 : Message
recipient=$1
subject=$2
message=$3

date=`date --rfc-2822`

# Replace linefeeds (LF) with CRLF and send message
sed 's/$/\r/' <<EOF | msmtp --account $MSMTP_ACCOUNT $recipient
From: <$FROM>
To: <$recipient>
Subject: $subject
Date: $date
$message
EOF