garrett_mailer.py

#!/usr/bin/env python
#
# author: Garrett Squire, gsquire
#
# 08/05/2015
#
import argparse
import os
import sys

from email.parser import Parser

import sendgrid

def sendmail_file(rfc_file):
    with open(rfc_file, 'r') as mail:
        headers = Parser().parse(mail)

    # After parsing the email, setup the parameters for the SendGrid
    # API usage.
    sg_client = sendgrid.SendGridClient(os.environ['SENDGRID_API_KEY'])

    mail = sendgrid.Mail()
    mail.add_to(headers['to'])
    mail.set_from(headers['from'])
    mail.set_from_name(headers['sender'])
    mail.set_subject(headers['subject'])
    mail.set_date(headers['date'])

    # This payload method returns a list of message objects. Text first, then
    # html and we want return them as a string for the API.
    mail.set_text(headers.get_payload()[0].as_string())

    # We strip the first 4 lines out of the HTML because they are specifiying
    # that it is an HTML document, thus unnecessary.
    stripped_html = headers.get_payload()[1].as_string().split('\n')[4:]
    mail.set_html('\n'.join(stripped_html))

    status, msg = sg_client.send(mail)
    if status == 200:
        print 'Sent the email.'
    else:
        print 'Something went wrong: ' + msg

def sendmail_input(to, subject, from_email, text="", cc=[], bcc=[]):
    """
    Form an email through the API with positional command line arguments.
    """
    sg_client = sendgrid.SendGridClient(os.environ['SENDGRID_API_KEY'])

    mail = sendgrid.Mail()
    mail.add_to(to)
    mail.set_subject(subject)
    mail.set_from(from_email)
    mail.set_text(text.read())
    mail.add_cc(cc)
    mail.add_bcc(bcc)

    # Close the text file as it was opened during argument parsing.
    text.close()

    status, msg = sg_client.send(mail)
    if status == 200:
        print 'Sent the email.'
    else:
        print 'Something went wrong: ' + msg
    
def main():
    # This is a when an email is read from an RFC 822 compliant file.
    if len(sys.argv) == 2:
        sendmail_file(sys.argv[1])
        sys.exit(0)

    args = argparse.ArgumentParser()
    args.add_argument('--to', nargs='*', required=True)
    args.add_argument('--subject', required=True)
    args.add_argument('--from', required=True)
    args.add_argument('--text', type=file, required=True)
    args.add_argument('--cc', nargs='*')
    args.add_argument('-bcc', nargs='*')

    # This makes an accessible dictionary for the arguments.
    cl_values = vars(args.parse_args())

    sendmail_input(cl_values['to'], cl_values['subject'], cl_values['from'],
            cl_values['text'], cl_values['cc'], cl_values['bcc'])

if __name__ == '__main__':
    main()