We recently migrated to Exchange 2010 and are currently in co-existence with Exchange 2003. We moved a few mailboxes over to 2010 for testing purposes and now those users are not able to view embedded images inside of Outlook. We checked the Outlook Trust Center settings and it is not set for "Don't download pictures..." This is a mix of Outlook 2007 and 2010 users. We have one MB/CAS/HT and one CAS/HT server, no edge transport. If I send an email from my personal account to 2 users at work, one of them being on 2003 and one being on 2010, the user whose mailbox is still in 2003 will get the picture just fine.
Any ideas?