mailsend.sh - Mail sending script with SMTPS and SMTP-AUTH using OpenSSL

mailsend.sh

#!/usr/bin/env bash

function PLAIN ()
{
  local u p
  read -p "Username: "    u
  read -p "Password: " -s p
  [ -z "$u" -a -z "$p" ] && return
  echo -en "$u\0$u\0$p" | base64
}

function mailsend () # <server> <port> <mailaddr>
{
  local MAIL_FROM="<$3>"
  local RCPT_TO="<$3>"
  local SMTP_HOST=$1
  local SMTP_PORT=$2
  local plain="$(PLAIN)"
  echo
  
  {
    cat<<-EOD
		EHLO localhost
		${plain:+AUTH PLAIN ${plain}$'/n'}MAIL FROM: ${MAIL_FROM}
		RCPT TO: ${RCPT_TO}
		DATA
		Subject: test
		From: ${MAIL_FROM}
		To: ${RCPT_FROM}
		
		test
		
		.
		QUIT
		EOD
    sleep 1
    } | openssl s_client -quiet -verify_quiet -connect $SMTP_HOST:$SMTP_PORT ${SERVERNAME:+-servername SERVERNAME}
}

if [ "$0" = "$BASH_SOURCE" ]; then
  if (( $# != 3 )); then
    cat <<-EOD
		Usage: ${0##*/} <server> <port> <mailaddr>
		
		EOD
    exit
  fi
  mailsend "$@"
fi