After looking deeper into the problem, I found that it is not related to utf-8, because it happens even with iso-8859-1.
The bug reports that I was reading are quite old, so it is possible that the problem may not exist in newer versions of php. However, I am unable to test it at present because we only use PHP 4.3.2. I was reading here (especially #23192)
http://bugs.php.net/search.php?cmd=disp ... mimeheader
but you can see that the problem report is quite old and the problem was not even considered a bug.
Here are the relevant mail headers:
- Code: Select all
Date: Mon, 02 Oct 2006 11:11:24 -0600 (MDT)
Date-warning: Date header was inserted by xxxx.xxxx.xxxx
Subject: [TJ] Submission Acknowledgement - This is test of very long subject
To: xxxxxxx <xxxxxxx@xxxxxxx>
test of very long subject line, test of very long
Content-Type: text/plain; charset="utf-8"
X-Mailer: Open Journal Systems v2
From: xxxxxxx <xxxxxxx@xxxxxxx>
Date: Mon, 2 Oct 2006 11:11:24 -0600 (MDT)
The subject line was probably broken with extra line break (it may be OS specific I guess), so it was pushed down to the body of the email. So the mail server thought "message-id", "date", "content-type" were missing and created them again.