I have a single Exchange Server 2010 SP2 RU6 with about 50 mailboxes that is running in single site/domain without any major concerns. Nearly all clients are Windows 7 running Outlook 2010 Professional (x86) (some SP1, some not).
I have only one client that is experiencing issues with Outlook. It seems that they are randomly not getting emails until days later. The delayed emails can be group/individual, internal/external, it doesn't matter. It seems to be about 1-3 emails per day that don't arrive on time. I've been having the user login to OWA every morning to check their inbox v. Outlook and the emails do arrive in OWA, but not in Outlook so I would think it's client issue and not Exchange. However, I've never seen an issue like this and I'm not sure what the problem would be.
Steps I've already tried:
a) repairing Office 2010
b) delete and create new mail profile for Outlook
c) disable Exchange Cached mode in Outlook and delete the OST file
None of which seem to provide any help. Thank you in advance for any assistance.