Hi,
I'm strugling with quite an unpleasant issue with yahoo mailservers, and they seem to be right this time. I checked the message sent from Roundcube and see that To: and Subject: headers are duplicated.
...
To: "user" <user@example.com>
Subject: Test
X-PHP-Originating-Script: 1014:rcube.php
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="=_2a5b0094597d18722a74778e1c598633"
Date: Mon, 07 Sep 2015 20:02:15 +0200
From: "user2" <user2@example.com>
To: "user" <user@example.com>
Subject: Test
Message-ID: <c754e762ffd019cbf30b4147e4dfaeea@example.com>
X-Sender: user2@example.com
User-Agent: Roundcube Webmail/1.1.1
Red part is generated by Roundcube (I checked it in Sent), while the green one is added "on-the-fly".
When I'm sending the same message from Outlook using SMTP headers are OK:
From: "user2" <user2@example.com>
To: "user2" <user2@example.com>
Subject: Test 2
Date: Mon, 7 Sep 2015 20:03:33 +0200
Message-ID: <006d01d0e997$831ace90$89506bb0$@razumovskiy.ru>
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_006E_01D0E9A8.46DCAFF0"
X-Mailer: Microsoft Outlook 15.0
Thread-Index: AdDpl4CByrL4cN0SQ0W7FqfEi0Cq8A==
Content-Language: ru
SMTP server is Postfix.
Those duplicate headers cause an error:
host mta6.am0.yahoodns.net[66.196.118.36] said: 554
Message not allowed - Headers are not RFC compliant[291] (in reply to end
of DATA command)
Would be grateful for any help!
Dimitriy