With listing 63, there is no from-adress and no subject in the sended email. Maybe there is a change in SMTPHandler.
My provider works with SSL/TLS so I have to change your listing and work with smtplib.SMTP_SSL. In this case I also changed the formatting of the mail-handler and use email.message for the message. After that all works ok.
I've attached my listing, so you can have a look at my solution.
Sorry for my poor english.
Michael
Listing 63 init .txt