A small script to send mails with attachements from command line.

send_mail.py

#!/usr/bin/python3
# -- Content-Encoding: UTF-8 --
"""
Sends e-mails with attachments

:author: Thomas Calmant
:copyright: Copyright 2014, isandlaTech
:license: Apache License 2.0
:version: 0.0.1
:status: Alpha

..

    Copyright 2014 isandlaTech

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
"""

# Module version
__version_info__ = (0, 0, 1)
__version__ = ".".join(str(x) for x in __version_info__)

# Documentation strings format
__docformat__ = "restructuredtext en"

# ------------------------------------------------------------------------------

from configparser import ConfigParser
from email import encoders
from email.header import Header
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import COMMASPACE
import argparse
import mimetypes
import os
import smtplib


def send_mail(server, port, send_from, send_to, subject, text, files=None,
              starttls=True, user=None, password=None):
    """
    Sends an email
    :param server: SMTP server
    :param port: SMTP server port
    :param send_from: Mail sender
    :param send_to: Recipients
    :param subject: Mail subject
    :param text: Content of the mail
    :param files: List of files to send
    :param starttls: Use TLS
    :param user: SMTP user name
    :param password: SMTP user password
    """
    assert isinstance(send_to, (tuple, list, set))

    # Prepare the main message
    outer = MIMEMultipart()
    outer['Subject'] = Header(subject, 'utf-8')
    outer['To'] = COMMASPACE.join(send_to)
    outer['From'] = send_from
    outer.attach(MIMEText(text, 'plain', 'utf-8'))

    for filepath in files or []:
        with open(filepath, "rb") as fp:
            # Guess type of file
            ctype, encoding = mimetypes.guess_type(filepath)
            if ctype is None:
                ctype = 'application/octet-stream'
            maintype, subtype = ctype.split('/', 1)

            # Prepare the attachment
            attachement = MIMEBase(maintype, subtype)
            attachement.set_payload(fp.read())

            # Encore payload
            encoders.encode_base64(attachement)

            attachement.add_header("Content-Disposition", "attachment",
                                   filename=os.path.basename(filepath))

            # Attach it
            outer.attach(attachement)

    # Connect to the SMTP server
    smtp = smtplib.SMTP(server, port)
    smtp.ehlo()

    # Use TLS
    if starttls:
        smtp.starttls()
        smtp.ehlo()

    # Login
    if user:
        smtp.login(user, password)

    # Send mail
    print("Sending mail to:", ", ".join(send_to))
    smtp.sendmail(send_from, send_to, outer.as_string())
    smtp.close()


def main(send_to, subject, text, files=None, config_file=None):
    """
    Reads a configuration file and sends mails
    """
    # Compute configuration file path
    home = os.path.expanduser("~")
    home_config_file = os.path.join(home, ".mail_sender")

    # Parse it
    parser = ConfigParser()
    try:
        for filepath in (home_config_file, config_file):
            if filepath:
                print("Reading configuration file:", filepath)
                parser.read(filepath)

        server = parser['server']
    except OSError as ex:
        print("Error reading file:", ex)
        return
    except KeyError:
        print("File has no 'server' section")
        return

    # Add configured elements
    try:
        mail = parser['mail']
    except KeyError:
        # No mail section
        pass
    else:
        if not subject:
            subject = mail.get('subject', "")

        if not send_to:
            send_to = [recipient.strip() for recipient in
                       mail.get('recipients', "").split(";")]

    # Send mail
    send_mail(server['host'], int(server['port'] or 25),
              server['from'], send_to, subject, text, files,
              server.getboolean('starttls', fallback=True),
              server.get('user'), server.get('password'))


def read_args(argv=None):
    """
    Read script arguments
    """
    if argv is None:
        import sys
        argv = sys.argv[1:]

    # Parse arguments
    parser = argparse.ArgumentParser(description="Mail sender script")
    parser.add_argument("--to", dest="send_to", nargs="+",
                        help="Mail recipients")
    parser.add_argument("--subject", dest="subject", help="Mail subject")
    parser.add_argument("--text", dest="text", help="Mail content",
                        default="<no content>")
    parser.add_argument("--files", dest="files", nargs="+",
                        help="Attached files")
    parser.add_argument("-c", "--configuration", dest="config_file",
                        help="Configuration file")

    return parser.parse_args(argv)


if __name__ == '__main__':
    # Read arguments
    args = read_args()
    main(args.send_to, args.subject, args.text, args.files,
         args.config_file)