groupwise has false positives
Scaning the following messages detects the address "myaddress@examples.com" as a permanent failure:
To: somewhere@example.com
Subject: Not a bounce
From: "Manuel Vázquez Acosta" <manuel@example.com>
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_019D_01D16E41.7138C310"
X-Mailer: Anything will do to trigger the bug
--text follows this line--
This is a multi-part message in MIME format.
------=_NextPart_000_019D_01D16E41.7138C310
Content-Type: text/plain
De: <myaddress@example.com>
------=_NextPart_000_019D_01D16E41.7138C310--
Some Microsoft Office Outlook versions are including the X-Mailer:
header and also use the Content-Type multipart/mixed. Below I show a real email fragment.
The bug is produced because groupwise.py only ask for:
if msg.get_content_type() != 'multipart/mixed' or not msg['x-mailer']:
return NoFailures
Any X-Mailer may confuse it if used in combination with the 'Content-Type: multipart/mixed', such as in this mail:
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_00C9_01D16E3D.BD956500"
X-Mailer: Microsoft Office Outlook, Build 11.0.5510
Thread-Index: AdFuZ6XxOH+qH5H+R76f2odV/Vn8MQ==
In-Reply-To: <1456018944.242038011550903.872471708902354@mercurio>
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180