Documentation

https://docs.python.org/3/library/email.examples.html#email-examples is providing code examples.
But those are 'incorrect' as they miss the "Date" header.
Without it, the mail recipient server will reject the email (Amavis/SpamAssassin is dropping the email due to a 'BAD-HEADER-0' error. I experienced that with : https://docker-mailserver.github.io/docker-mailserver/latest/ )

Related topic:

• smtplib send_message should add Date header if it is missing, per RFC5322 #73065

The correct headers in the examples should be:

msg = EmailMessage()
msg['Subject'] = "subject"
msg['From'] = "sender@example.com"
msg['To'] = "receiver@example2.com"
msg["Date"] = email.utils.formatdate(localtime=True)

I understand it's not "added automatically" but the examples could contain that. So a user can get it right the first time without wondering why emails are not received without any error as only the mail receiver server log would tell...

Linked PRs

• gh-107809: Include the Date header for email examples #107818