Python Programs - Sending Email using SMTP

• Sending Email

  Simple Mail Transfer Protocol (SMTP) is a protocol which handles sending e-mail and routing e-mail between mail servers.
  Python provides smtplib module which defines an SMTP client session object that can be used to send mail to any Internet machine with an SMTP or ESMTP listener daemon.

  Syntax:

  import smtplib
  
  smtpObj = smtplib.SMTP( [host [, port [, local_hostname]]] )
  
  Here is the detail of the parameters:
  1. host: This is the host running your SMTP server. You can specifiy IP address of the host or a domain name. This is optional argument.
  2. port: If you are providing host argument then you need to specifiy a port where SMTP server is listening. Usually this port would be 25.
  3. local_hostname: If your SMTP server is running on your local machine then you can specify just localhost as of this option.
  An SMTP object has an instance method called sendmail, which will typically be used to do the work of mailing a message.
  It takes three parameters:
  1. The sender - A string with the address of the sender.
  2. The receivers - A list of strings, one for each recipient.
  3. The message - A message as a string formatted as specified in the various RFCs.

• Example

  #!/usr/bin/python
  
  import smtplib
  
  sender = 'from@fromdomain.com'
  receivers = ['to@todomain.com']
  
  message = """From: From Person < from@fromdomain.com >
  To: To Person < to@todomain.com >
  Subject: SMTP e-mail test
  
  This is a test e-mail message.
  """
  
  try:
     smtpObj = smtplib.SMTP('localhost')
     smtpObj.sendmail(sender, receivers, message)
     print "Successfully sent email"
  except SMTPException:
     print "Error: unable to send email"