I need to be able to force emails to and from one particular storage group in our Exchange 2007 (sp3) organisation over SMTP to our external smarthost who will then immediately relay the email back into our organisation. We have a single domain with a single Exchange organisation with one single SMTP suffix.
We need to ensure that header information for emails to and from this particular SG have a complete inbound SMTP header and are processed by our external smarthost's antivirus/malware/antispam algorithms.
From a user point of view, mailboxes on either side of this connector will continue to use Outlook in the normal manner for internal recipients and the process should be completely transparent (i.e they will not be forced to use SMTP addresses to email their colleagues and all users should continue to have the same email suffix and primary email address). Other emails not involving this particular storage group should continue to be processed in the usual manner.
Does anyone have any idea of a mechanism on how we might achieve this?
Hope someone can help with this slightly odd request.