sending emails with python - subject of message missing

Question

all. I have encountered a bit of a problem while trying to send emails with python's email package along with smtplib. I have set up a function that send an email and it works well, with the exception that the email always comes without the subject. I am not new to python, but I am new to using it for internet-related things such as this one. I have set up the following from several answer in this forum as well as the examples in the documentation.

import smtplib
from os.path import basename
from email import encoders
from email.mime.application import MIMEApplication
from email.mime.base import MIMEBase
from email.mime.audio import MIMEAudio
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import COMMASPACE, formatdate
def send_mail(send_from, send_to, subject, text, files=None, server="smtp.gmail.com"):
    import mimetypes
    assert isinstance(send_to, list)
    msg = MIMEMultipart(From=send_from, To=COMMASPACE.join(send_to), Date=formatdate(localtime=True), Subject=subject)
    msg.attach(MIMEText(text))
    for f in files or []:
            print f
            ctype,encoding=mimetypes.guess_type(f)
            if ctype is None or encoding is not None:
                    ctype = 'application/octet-stream'
            maintype, subtype = ctype.split('/', 1)
            if maintype == 'text':
                    fp = open(f)
                    msg = MIMEText(fp.read(), _subtype=subtype)
                    fp.close()
            elif maintype == 'image':
                    fp = open(f, 'rb')
                    msg = MIMEImage(fp.read(), _subtype=subtype)
                    fp.close()
            elif maintype == 'audio':
                    fp = open(f, 'rb')
                    msg = MIMEAudio(fp.read(), _subtype=subtype)
                    fp.close()
            else:
                    fp = open(f, 'rb')
                    msg = MIMEBase(maintype, subtype)
                    msg.set_payload(fp.read())
                    fp.close()
                    encoders.encode_base64(msg)
            msg.add_header('Content-Disposition', 'attachment', filename=basename(f))
    smtp = smtplib.SMTP(server)
    smtp.starttls()
    usrname=send_from
    pwd=raw_input("Type your password:")
    smtp.login(usrname,pwd)
    smtp.sendmail(send_from, send_to, msg.as_string())
    smtp.close()

Calling the function as send_mail('john@doe.com',['john@doe.com'],'This is the subject','Hello, World!') results in an email sent correctly but without a subject.

The output with or without files is the same. Also, reading the docs also didn't help me.

I appreciate any help.

Answer 1

Instead of passing subject as an argument to MIMEMultipart, try assigning the value to msg:

msg['Subject'] = subject

Great examples in the docs: https://docs.python.org/3/library/email-examples.html