Michal Sladek <michal at sladkovi.eu> added the comment:
I tested the code again. Using Gmail SMTP server produces correct results, using server smtp.seznam.cz leads to a problem (I should mention here, that Seznam is the largest free mail provider in the Czech Republic). Here are the differences on receiving side.
GMAIL:
Return-Path: <michal at sladkovi.eu>
Received: from mail-bk0-f45.google.com (mail-bk0-f45.google.com [209.85.214.45])
by mx4.volny.cz (Postfix) with ESMTP id 0A3E12E086B
for <msladek at volny.cz>; Tue, 13 Mar 2012 17:58:03 +0100 (CET)
Received: by bkcjg9 with SMTP id jg9so842625bkc.18
for <msladek at volny.cz>; Tue, 13 Mar 2012 09:58:03 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=google.com; s=20120113;
h=message-id:date:content-type:mime-version:from:to:subject
:x-gm-message-state;
bh=Sdb8G6CtN+pEzPJHxwbwCprTgWPJUrR3jiU+qeK1WAs=;
b=X88feHvtpL6zBXYNYSjgUQ+1WirGmU8B69k+4fGlAge6F5+pYd6SzuJ6ExdBsp+brw
1QuCne97OdVnYoFmg86ZviFz3m6Cn6N8hgPNa2H7hCPQD4O+cjJQQzze4xXYqgPJQs+D
ke4ISEmxL9UFJUvkTyFhrCDefSxQMY+TnnLwWQR+PCD/uB0FgR2UgBjEx9K7EUKQi6W0
78+EZYO3cd+SuuadOUvIpe2cj0576ahcP40dGN0kIe+P4NX5Ij7D2cCa/bWiwFdDRUI4
v8UxJcnbTuOCQFtlItxCAxU9IzZWGekWtpJVnRDBGG63iGXHoTDzp+4+d1FRBGsDQ2pD
l5tg==
Received: by 10.204.150.73 with SMTP id x9mr6371797bkv.7.1331657883687;
Tue, 13 Mar 2012 09:58:03 -0700 (PDT)
Received: from dvr.ph.sladkovi.eu (ip-84-42-150-218.net.upcbroadband.cz. [84.42.150.218])
by mx.google.com with ESMTPS id u14sm2783344bkp.2.2012.03.13.09.58.02
(version=SSLv3 cipher=OTHER);
Tue, 13 Mar 2012 09:58:02 -0700 (PDT)
Message-ID: <4f5f7c9a.0e70cc0a.12f5.75a3 at mx.google.com>
Date: Tue, 13 Mar 2012 09:58:02 -0700 (PDT)
Content-Type: multipart/mixed; boundary="===============1165280172=="
MIME-Version: 1.0
From: michal at sladkovi.eu
To: msladek at volny.cz
Subject: =?utf-8?b?xb5sdcWlb3XEjWvDvSBrxa/FiA==?=
X-Gm-Message-State: ALoCoQmf6k2GVVKdm0ZNbvSyPpZ0Gl1yv/BDc3h3zrh34hWWp3wa/fSBXbWT9FANzBLd5k1qUnEP
X-DKIM-Status: neutral
X-Virus: no (m2.volny.internal - Tue, 13 Mar 2012 17:58:05 +0100 (CET))
X-Spam: no (m2.volny.internal - Tue, 13 Mar 2012 17:58:07 +0100 (CET))
X-Received-Date: Tue, 13 Mar 2012 17:58:08 +0100 (CET)
--===============1165280172==
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64
w7pwxJtsIMSPw6FiZWxza8OpIMOzZHk=
--===============1165280172==--
--------------------------------------------------------------
SEZNAM:
Return-Path: <Michal.Sladek at seznam.cz>
Received: from smtp2.seznam.cz (smtp2.seznam.cz [77.75.76.43])
by mx4.volny.cz (Postfix) with ESMTP id 542A32E0868
for <msladek at volny.cz>; Tue, 13 Mar 2012 18:00:05 +0100 (CET)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=seznam.cz;
h=Received:Content-Type:MIME-Version:From:To:Subject:--===============1097187749==:MIME-Version:Content-Transfer-Encoding:X-Smtpd:X-Seznam-User:X-Session:X-Country:X-Virus-Info:X-Seznam-SPF:X-Seznam-DomainKeys;
b=bfwTOSoFJU7vGbB7VvXNIQzhbsj+pDPhwr72BX1aVWAicyK0Cix3evz6c3+srYBba
lHDeYd74ZXW5553N6ocfy68pRxpI6K5dKfvcKKLgUN7+N/iQOUtj09D4wN81cjPt7qQ
uH5rjcdsDsbZV31EsxyS1P/rn6F7bYOxrpPeHAk=
Received: from dvr.ph.sladkovi.eu (ip-84-42-150-218.net.upcbroadband.cz [84.42.150.218]) by email-relay1.ng.seznam.cz (Seznam SMTPD 1.2.15-6 at 18976) with ESMTP; Tue, 13 Mar 2012 17:59:32 +0100 (CET)
Content-Type: multipart/mixed; boundary="===============1097187749=="
MIME-Version: 1.0
From: Michal.Sladek at seznam.cz
To: msladek at volny.cz
Subject: =?utf-8?b?xb5sdcWlb3XEjWvDvSBrxa/FiA==?=
X-DKIM-Status: fail
X-Virus: no (m2.volny.internal - Tue, 13 Mar 2012 18:00:06 +0100 (CET))
X-Spam: no (m2.volny.internal - Tue, 13 Mar 2012 18:00:08 +0100 (CET))
X-Received-Date: Tue, 13 Mar 2012 18:00:08 +0100 (CET)
--===============1097187749==:Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: base64
X-Smtpd: 1.2.15-6 at 18976
X-Seznam-User: michal.sladek at seznam.cz
X-Session: 5
X-Country: CZ
X-Virus-Info:clean
X-Seznam-SPF:neutral
X-Seznam-DomainKeys:unknown
w7pwxJtsIMSPw6FiZWxza8OpIMOzZHk=
--===============1097187749==--
--------------------------------------------------------------
As you can see, Seznam is adding a lot of headers into mail's body. Anyway, making utf-8 subject manually like this:
base64Subject = base64.b64encode(subject.encode('utf-8')).decode()
encodedSubject = '=?UTF-8?B?{0}?='.format(base64Subject)
message.add_header('Subject',encodedSubject)
works correctly for both SMTP servers. So there must be a difference...
----------
_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue14062>
_______________________________________