Outlook connectivity and mail flow issue on Exchange 2010 3 node DAG

Hi,

I have 3 node DAG, 2 (NODE A, NODE B) in Production site and 1(NODE C) in DR site. but just 1 AD Site.

when I have the active databases on NODE B, everything works fine. no issues to report.

but when I move the databases on NODE A, outlook gets connected with trying to update folders. Furhter, emails will be in outbox and no new emails will be delivered to the users. After an hour or so emails get delivered from outbox.

Even after supplying the credentials OWA doesnt login. just tries to load.

No issues when I move the servcies on NODE C.

ANy idea what could be the issue?

Thanks,

Vinod