SMTP error (cannot send) when sending rich text format (RTF) messages

OS X 10.4.11 and Mail 2.1.1 AND OS X 10.5.1 and Mail 3.1

All of these, I believe, were released on 11/15/07, which is the same date we started having the problems described below. At 2 a.m. that same date -- yes, before I knew about the OS X updates -- I began moving our mail server to a new machine and because it was a newer server OS I had to upgrade the mail server software, too. How is that for an unfortunate coincidence?

Here are the problems:

WITH Preferences, Composing SET to Message Format: Rich Text and/or Use the same message format as the original message CHECKED

THEN doing ANY of the following:

Replying to a message in RTF format that has a URL link,
Forwarding a message in RTF format that has an attachment or a URL link,
Creating a new message in RTF format with an attachment or URL link

WHEN sending Mail connects to the SMTP server and after receiving the 354 command from the server it times out.


During the connection Activity Viewer shows "Delivering message Sending Data (100% done)". I believe it is referring to the DATA command it sends to the mail server. After the connection times out Mail gives an error dialog that shows "Cannot send message using the server mail.domain.com The server response was: An error occurred while delivering this message via the SMTP server "(null)" " etc.


The mail server is Mdaemon 8.1.3 running on Windows Server 2003. The transcript from the Mdaemon session log for one of these unsuccessful SMTP sessions is:

Mon 2007-11-26 15:04:10: ----------
Mon 2007-11-26 15:04:21: Session 9044; child 6; thread 1040
Mon 2007-11-26 14:54:22: Accepting SMTP connection from [70.62.213.174 : 60457]
Mon 2007-11-26 14:54:22: --> 220-domain.com ESMTP MDaemon 8.1.3; Mon, 26 Nov 2007 14:54:22 -0500
Mon 2007-11-26 14:54:22: --> 220 Unauthorized relay prohibited. All connections are logged.
Mon 2007-11-26 14:54:22: <-- EHLO [192.168.1.108]
Mon 2007-11-26 14:54:22: --> 250-domain.com Hello [192.168.1.108], pleased to meet you
Mon 2007-11-26 14:54:22: --> 250-ETRN
Mon 2007-11-26 14:54:22: --> 250-AUTH=LOGIN
Mon 2007-11-26 14:54:22: --> 250-AUTH LOGIN CRAM-MD5
Mon 2007-11-26 14:54:22: --> 250-8BITMIME
Mon 2007-11-26 14:54:22: --> 250 SIZE 0
Mon 2007-11-26 14:54:23: <-- MAIL FROM:<user1@domain.com>
Mon 2007-11-26 14:54:23: --> 250 <user1@domain.com>, Sender ok
Mon 2007-11-26 14:54:23: <-- RCPT TO:<user2@domain,com>
Mon 2007-11-26 14:54:23: --> 250 <user2@domain.com>, Recipient ok
Mon 2007-11-26 14:54:23: <-- DATA
Mon 2007-11-26 14:54:23: Creating temp file (SMTP): e:\mdaemon\queues\temp\md50000022800.tmp
Mon 2007-11-26 14:54:23: --> 354 Enter mail, end with <CRLF>.<CRLF>
Mon 2007-11-26 15:04:21: Connection timed out!
Mon 2007-11-26 15:04:21: SMTP session terminated (Bytes in/out: 100/410)
Mon 2007-11-26 15:04:21: ----------

(KEY: --> = Mdaemon server, <-- = Mail client)

This example is from one local account to another local account but it doesn't matter, it also happens when sending to a non-local account. Note that the Mail client reports that the server responded with "an error occurred" but the server's session transcript does not show sending an error response.


This ONLY happens with the above OS and Mail versions. It does not happen with OS X 10.4.10 and Mail 2.1 except for a notable exception, which is if a 10.4.10/2.1 user is replying to or forwarding one of the three types of emails described above that originated from a 10.4.11/2.1.1 user (and, I presume, a 10.5.1/3.1 user although I have not tested that).

It does NOT happen when sending those types of emails using Entourage on OS X 10.4.11, Thunderbird on OS X 10.4.11, Outlook on Windows XP Pro or Outlook Express on Win XP Pro from the same LAN accessing the same mail server.

It also DOES happen with OS X 10.4.11 - Mail 2.1.1 users and OS X 10.5.1 - Mail 3.1 users accessing the same mail server from other locations, i.e. at their home, wireless hot spots, etc.

The WORKAROUND is to change the Preferences to always send messages using plain text. Also, opening any of the messages that can't be sent from the outbox, changing them to plain text and sending them again will get them sent successfully.

But we need a permanent solution. We need to be able to send rich text messages, especially with URL links, and attachments.

Help please. Thanks in advance. Jeff.