如何使用Python发送经过身份验证的电子邮件？

Question

I have a python function to send an email notification. I have included the login call to authenticate with my local SMTP server, however emails are being returned stating '553-mail rejected because your IP is in the PBL'. Further reading on https://www.spamhaus.org/pbl reveals that apparently I am not being prevented from sending email, I am simply required to authenticate first.

I have tried base64 encoding to avoid sending the password as plain text without success.

I have also looked at the Pysasl library, but I am a little unsure how I might use this for authenticating with my SMTP server.

Would anyone have any guidance as to the correct use of either base64 encoding, the pysasl library or if a better method exists for satisfying the correct authentication requirements?

My code is below.

def emailNotify(self,userid):
    SMTPserver = 'localhost'
    sender = '***'  # blanked
    username = '***' # blanked
    receiver = '***' # blanked
    pwd = '***'  # blanked
    text_subtype = 'plain'

    msg = 'requested data was posted to dashboard for '+userid

    subject = 'confirmation of POST\'d data for '+userid

    try:
        msg = MIMEText(msg, text_subtype)
        msg['Subject'] = subject
        msg['From'] = sender

        conn = smtplib.SMTP(SMTPserver)
        conn.login(username, pwd)
        try:
            conn.sendmail(sender, receiver, msg.as_string())
        finally:
            conn.quit()
    except:
        print('message sending failed')

Thanks in advance.

Answer 1

You have 2 ways of building a program for sending mail:

• build a bullet proof solution:

  • analyze what server announces as its capabilities
  • choose the one that better meets your requirement
  • use that authentication method
  • actually send the mail

  simply that means that you have to implement code for reading and decoding what the server returns (which can be weird) and also all various authentication methods, not speaking of TLS

• use a custom connection method adapted to that server

  • read the documentation of the server to know what it declares to support
  • test it manually first through a mere telnet connection then in an interactive Python session (idle is enough here, but you can choose your prefered Python shell)
  • carefully program the way you have just tested - but leave relevant error messages in cases the server capabilities change...

  IMHO much simpler...