I have Outlook 2007 sp1 running on windows vista business edition. I have an
email account setup pointing at my isp POP/SMTP server. When I send out email
the SMTP Message-ID header created by Outlook includes multiple @ characters
which is invalid per RFC 822. In particular it gets marked as SPAM by spam
detection engines.

Here is a typical set of headers when I send out email:

[code]
Reply-To: xxxx.y...@xxx.co.uk
From: "Robin East" xxxx.y...@xxx.co.uk
To: <xxxx.y...@xxx.co.uk>
Subject: testt
Date: Wed, 19 Mar 2008 12:30:54 -0000
Organization: xxxxxxxx
Message-ID: <012301c889bd$18b3cd00$4a1b6700$@yyyy@xxxxx.co.uk>
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0124_01C889BD.18B3CD00"
X-Mailer: Microsoft Office Outlook 12.0
thread-index: AciJvRL2+wLvIbvzTWCpnZadQdnxsA==
Content-Language: en-gb
X-2020-Relay: Sent using 2020MEDIA.net.uk relay with auth code: xxxxx
Send Abuse reports to ab...@2020media.net.uk
X-UIDL: SV9"!f-C!!Pc&#!17D"!
[/code]

I know this has been covered off in
http://www.microsoft.com/communities/newsgroups/list/en-us/default.as...
but I don't think we got to the bottom of the problem there. Anyone got any
further thoughts on this?