Email send error: "See http://pobox.com/~djb/docs/smtplf.html"

[maherma-adg]

I found a bug sending multipart emails from django 1.6 (over python3) when target mail server is QMail.

The received error is "451, See ​http://pobox.com/~djb/docs/smtplf.html"

Tracing code show me that multipart encode data is generated with "\n" line separator which violate email specifications.

Test enviroment:
OSX 10.9.4
Django 1.6.6
Python 3.4.1
Mail server: QMail

You can fix this issue modifing this line in file /core/mail/message.py:153

- g.flatten(self, unixfrom=unixfrom)
+ g.flatten(self, unixfrom=unixfrom, linesep = '\r\n')

This modification replace lineseparator in multipart data from \n to \r\n allowing mails to be sent.

This is not a permanent fix but can be a starting point.

Manuel.

[Aymeric Augustin]

The doc for ​flatten says:

Optional linesep specifies the line separator character used to terminate lines in the output. If specified it overrides the value specified by the msg's or Generator's policy.

Since Django doesn't specify a policy, I believe we end up with ​the default policy, which is documented to exhibit this bug. The proper fix is to switch to ​the SMTP policy.

The easiest way is to inject it when we instanciate the Generator. But I'm wondering if it wouldn't be safer to set it on the message, to avoid the same kind of bugs in other code paths.

[Florian Apolloner]

Closing in favor of #23063 which is the older ticket (and I like tcpdumps ;))