We are currently using CRM 4.0 and UR17 and have an issue with tracked emails using guids instead of standard Exchange Message IDs(see
http://support.microsoft.com/kb/2554541/) I have implemented the registry fix in the KB but I still get the error, namely UNTRACKED emails get sent to the user, whereas TRACKED emails bounce with "Remote
host said: 553 5.0.0 Message-Id header line format error" as MessageID verification is in use.
Short of upgrading the server and all users to UR21, is there any way I can resolve this error? I have tried restarting the CRM server. Our email platform is Exchange 2010.