Gmail dumps patch review email in my junk box. The problem seems to be
the spoofed From: header.

Received: from psf.upfronthosting.co.za ([2a01:4f8:131:2480::3])
         by mx.google.com with ESMTP id
m1si26039166wjy.52.2015.05.12.00.20.38
         for <tjreedy@udel.edu>;
         Tue, 12 May 2015 00:20:38 -0700 (PDT)
Received-SPF: softfail (google.com: domain of transitioning
storchaka@gmail.com does not designate 2a01:4f8:131:2480::3 as permitted
sender) client-ip=2a01:4f8:131:2480::3;

Tracker reviews are the only false positives in my junk list. Otherwise,
I might stop reviewing. Verizon does not even deliver mail that fails
its junk test, so I would not be surprised if there are people who
simply do not get emailed reviews.

Tracker posts are sent from Person Name <report@bugs.python.org>
Perhaps reviews could come 'from' Person Name <review@bugs.python.org>

Even direct tracker posts just get a neutral score.
Received-SPF: neutral (google.com: 2a01:4f8:131:2480::3 is neither
permitted nor denied by best guess record for domain of
roundup-admin@psf.upfronthosting.co.za) client-ip=2a01:4f8:131:2480::3;

SPF is Sender Policy Framework
https://en.wikipedia.org/wiki/Sender_Policy_Framework

Checkins mail, for instance, gets an SPF 'pass' because python.org
designates mail.python.org as a permitted sender.

--
Terry Jan Reedy