SMTP backend should try harder to figure out the local host name

[Jacob]

Django's SMTP backend sets the local_hostname argument to smtplib.SMTP by calling socket.getfqdn() (via django.core.mail.utils.DNS_NAME, which caches that result). smtplib itself uses a slightly more robust method (see smtplib around line 245) if local_hostname isn't given.

In certain circumstances this can mean that sending mail through smtplib directly works, but sending it via django.core.mail fails.

We could solve this by just passing local_hostname=None, but that'd result in a DNS lookup every time we send email, which is silly (and which is why we're caching it in the first place).

So, DNS_NAME should use similar logic to smtplib to try harder to get the DNS hostname.

[anonymous]

Forgot to comment -- but trivial patch attached, copies the logic from python's standard smtplib. Should be ready for checkin but this is my first contribution so I'll leave this as-is (Accepted, has_patch).

[Russell Keith-Magee]

Sorry - but this isn't RFC.

It doesn't contain a test case, and it doesn't contain a compelling argument for why tests aren't plausible. It doesn't even contain a clear description of why the change is needed other than suggesting "certain circumstances" under which it will be needed.

It also seems to assume that the result of socket.gethostbyname(socket.gethostname()) will be an IPv6 address, which I'm pretty sure isn't correct.

[Jacob]

Milestone 1.3 deleted

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Sam Kuffer]

Duplicate of #6989