Use EHLO after smtplib.SMTP_SSL too.

[kchmiela]

In file django/core/mail/backends/smtp.py after smtplib.SMTP_SSL EHLO should be used.

[kchmiela]

Patch

[Tim Graham]

I haven't looked at the history behind this yet, but in reading ​the Python docs:

Unless you wish to use has_extn() before sending mail, it should not be necessary to call this method explicitly. It will be implicitly called by sendmail() when necessary.

I don't see a has_extn() call in Django, so maybe the call can be removed?

[Emett Speer]

Well you are correct in all currently supported versions of Python it does state that its not needed unless using has_extn().

[Tim Graham]

The ticket is missing the rationale of what problem is being solved. Is it to detect communication failures in open() rather than wait until sending a message? Maybe ehlo_or_helo_if_needed() should be used instead?

django/core/mail/backends/smtp.py

@@ -56 +56 @@
             })
         try:
             self.connection = connection_class(self.host, self.port, **connection_params)
+            self.connection.ehlo_or_helo_if_needed()
 
             # TLS/SSL are mutually exclusive, so only attempt TLS over
             # non-secure connections.
             if not self.use_ssl and self.use_tls:
-                self.connection.ehlo()
                 self.connection.starttls(keyfile=self.ssl_keyfile, certfile=self.ssl_certfile)
-                self.connection.ehlo()
             if self.username and self.password:
                 self.connection.login(self.username, self.password)
             return True

Anyway, tests are still needed.

[Claude Paroz]

In my opinion, both ehlo() calls could be deleted, and nothing should be added. starttls, login and other connection methods are caring for that themselves. However, they should not be harmful either.

If there is a real problem with EmailBackend not calling ehlo(), please provide more details.

[Tim Graham]

The docs for ​starttls() say, "You should then call ehlo() again." This might be an obsolete requirement as the sendmail() and login() method's in Python's Lib/smtplib.py call self.ehlo_or_helo_if_needed(). I'm not familiar with the SMTP protocol though so I'm not positive what this all means.

[Tim Graham]

I'll ​remove the ehlo() calls and close this ticket as "needsinfo" unless anyone can explain why the change proposed in the ticket's description is needed.

[GitHub <noreply@…>]

In bcae045d:

Refs #26487 -- Removed unneeded ehlo() calls in SMTP backend.

starttls(), login(), and other connection methods already call
the method as needed.