send_emails.py

# for getting full paths to attachements
import os
# for encoding messages in base64
from base64 import urlsafe_b64encode
# for dealing with attachement MIME types
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.image import MIMEImage
from email.mime.audio import MIMEAudio
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from mimetypes import guess_type as guess_mime_type

from common import our_email, gmail_authenticate

# Adds the attachment with the given filename to the given message
def add_attachment(message, filename):
    content_type, encoding = guess_mime_type(filename)
    if content_type is None or encoding is not None:
        content_type = 'application/octet-stream'
    main_type, sub_type = content_type.split('/', 1)
    if main_type == 'text':
        fp = open(filename, 'rb')
        msg = MIMEText(fp.read().decode(), _subtype=sub_type)
        fp.close()
    elif main_type == 'image':
        fp = open(filename, 'rb')
        msg = MIMEImage(fp.read(), _subtype=sub_type)
        fp.close()
    elif main_type == 'audio':
        fp = open(filename, 'rb')
        msg = MIMEAudio(fp.read(), _subtype=sub_type)
        fp.close()
    else:
        fp = open(filename, 'rb')
        msg = MIMEBase(main_type, sub_type)
        msg.set_payload(fp.read())
        fp.close()
    filename = os.path.basename(filename)
    msg.add_header('Content-Disposition', 'attachment', filename=filename)
    message.attach(msg)

def build_message(destination, obj, body, attachments=[]):
    if not attachments: # no attachments given
        message = MIMEText(body)
        message['to'] = destination
        message['from'] = our_email
        message['subject'] = obj
    else:
        message = MIMEMultipart()
        message['to'] = destination
        message['from'] = our_email
        message['subject'] = obj
        message.attach(MIMEText(body))
        for filename in attachments:
            add_attachment(message, filename)
    return {'raw': urlsafe_b64encode(message.as_bytes()).decode()}

def send_message(service, destination, obj, body, attachments=[]):
    return service.users().messages().send(
      userId="me",
      body=build_message(destination, obj, body, attachments)
    ).execute()


if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description="Email Sender using Gmail API")
    parser.add_argument('destination', type=str, help='The destination email address')
    parser.add_argument('subject', type=str, help='The subject of the email')
    parser.add_argument('body', type=str, help='The body of the email')
    parser.add_argument('-f', '--files', type=str, help='email attachments', nargs='+')

    args = parser.parse_args()
    service = gmail_authenticate()
    send_message(service, args.destination, args.subject, args.body, args.files)