MailViaServer3

#!/usr/bin/python

from __future__ import print_function


#-----------------------------------------------------------------------
#   Imports
#-----------------------------------------------------------------------
import os, sys, time, getopt, getpass, smtplib

#-----------------------------------------------------------------------
#   Constants
#-----------------------------------------------------------------------
PORT_STARTTLS = 587


#-----------------------------------------------------------------------
#   Functions
#-----------------------------------------------------------------------

def Usage(msg=None):
    print ("""
   MailViaServer3 [-h HELO_HOST ] [-f MAIL_FROM] -F<findstr> -R<replacestr> -s <server> {<msg-file>|-} <addr> [<addr> ...]

	Mails [file] (or standard in) to mail address <addr>
	through the mail server given by  -s <server>, or writes
	email to standard out.

   Options:

     -h HELO    Name of host passed in SMTP HELO command.
                Default is "%s".

     -f FROM    Return addressed passwd in SMTP MAIL FROM command.
                Default is "%s".

     -A FILE    Read addresses from FILE.  One address per line,
                blank lines and comments (#) are ignored.

     -F FINDSTR Find FINDSTR in <msg-file> and repace with REPSTR below.
                Both -F and -R can be repeated multiple times.

     -R REPSTR  See -F above

     -s SERVER  Send email via mail server SERVER.  If none given,
                email is formatted and sent to standard out.
                This is useful for testing.

     -t FILE    Use StartTLS on port %s.  Will read server host name, 
                email account name, and password, from first, second and
                third line.

     -T         Use StartTLS on port %s.  Will prompt user for account
                and password.

     -v         Display progress


   Example:

      This reads an email template from standard input.  It uses
      the -F and -R options to substitute the value of {NAME} in
      the template, and addresses the email to b.jones@example.com.
      The email is sent to the email server smtp.myplace.edu.
      The FROM address submitted to the email server is smith@myplace.edu.
      Note that this FROM address is not the same as the From: address
      used inside the email template.

      MailViaServer3 -f smith@myplace.edu -s smtp.myplace.edu -F{NAME} -RJohnboy - b.jones@example.com <<EOM
      > Subject:  This is a test message.
      > From: Another.place@another.time.com
      >
      > Hi there {NAME}
     > EOM
""" % (DEF_HELO, DEF_FROM, PORT_STARTTLS, PORT_STARTTLS))
    raise SystemExit

def print_error(msg):
	print()
	print("    ERROR: ", msg)
	print()
	sys.exit()

def get_addr_from_file(filename):
	return [line for line in [line.strip() for line in open(filename).readlines()] if line and line[0]!='#']

def process_opts(opts):
	newopts = {}
	findstr = []
	repstr  = []
	for k,v in opts:
		if k=='-F':
			findstr.append(v)
		elif k=='-R':
			repstr.append(v)
		else:
			newopts[k] = v
	return newopts, findstr, repstr

#  Read email user name and password from console
def get_user_pass():
	user   =           input("Enter email account name:     ")
	passwd = getpass.getpass("Enter email account password: ")
	return user, passwd

#  Read email user name and password from plain text file
def read_server_user_pass_file(fname):
	server_name, user, passwd = '', '', ''
	with open(fname) as fin:
		server_name = fin.readline().strip()
		user        = fin.readline().strip()
		passwd      = fin.readline().strip()
	return server_name, user, passwd

def write_verbose(msg):
	if VERBOSE:
		print("VERBOSE: ", time.strftime("%Y-%m-%d %H:%M:%D"), msg)
		

#-----------------------------------------------------------------------
#  Initialize Global Variables
#-----------------------------------------------------------------------

#  Default envelope from address: MAIL FROM: 
user = os.environ.get("USER","localuser")
host = os.environ.get("HOSTNAME","localhost")

DEF_FROM = user + "@" + host
DEF_HELO = host
VERBOSE  = False


#-----------------------------------------------------------------------
#  Main
#-----------------------------------------------------------------------
def main():
	global VERBOSE
	#  Get options
	opts, args = getopt.getopt(sys.argv[1:], "f:h:s:A:F:R:Tvt:");
	opts, findstr, repstr = process_opts(opts)
	helo         = opts.get('-h', DEF_HELO)
	from_address = opts.get('-f', DEF_FROM)
	addr_file    = opts.get('-A', None)
	server_name  = opts.get('-s', None)
	VERBOSE      = '-v' in opts

	#  Make sure number of findstr[] and repstr[] match
	if not len(findstr)==len(repstr):
		print_error("Number of find strings and replace strings don't match.")

	#  Get servername and msg-file from command-line
	try:
	    filename      = args.pop(0)
	except:
	    Usage()

	#  Get addresses from option or command-line
	if addr_file:
		to_addresses = get_addr_from_file(addr_file)
	else:
		#  If to_addresses not on command-line, show Usage
		try:
			to_addresses  = args
		except:
			Usage()

	#  Read mail message
	if filename=="-":
	    fin = sys.stdin
	    msg = fin.read()
	else:
	    fin = open(filename,"r")
	    msg = fin.read()
	    fin.close()

	#  Make sure all the find strings are in the message
	for s in findstr:
		if msg.find(s)==-1:
			print_error('Cannot find the findstr "%s" in mail file' % s)
			sys.exit()

	#  Replace string placeholders in message
	for i in range(len(findstr)):
		msg = msg.replace(findstr[i], repstr[i])

	#  Send message
	if server_name or '-t' in opts:
		#  Use STARTTLS
		if '-T' in opts or '-t' in opts:
			#  Get username and password
			if '-T' in opts:
				username, password = get_user_pass()
			else:
				config_server_name, username, password = read_server_user_pass_file(opts['-t'])
			#  Let user override configured server name with name from the command line
			if server_name==None: server_name = config_server_name
			write_verbose("STARTTLS: open server connection")
			sm = smtplib.SMTP(server_name, PORT_STARTTLS)
			write_verbose("STARTTLS: starttls")
			sm.starttls()
			write_verbose("STARTTLS: login")
			sm.login(username, password)
			write_verbose("STARTTLS: ehlo")
			sm.ehlo(helo)
			write_verbose("STARTTLS: sendmail")
			sm.sendmail(from_address, to_addresses, msg)
			write_verbose("STARTTLS: finished")
		#  Use standard SMTP (port 25)
		else:
			write_verbose("SMTP: open server connection")
			sm = smtplib.SMTP(server_name)
			write_verbose("SMTP: helo")
			sm.helo(helo)
			write_verbose("SMTP: sendmail")
			sm.sendmail(from_address, to_addresses, msg)
			write_verbose("SMTP: finished")
	else:
		print(msg)

main()