We have a few individuals that are having issues sending mail from their PC's. They have either Office 2010 SP2 or Office 2013 installed. When they send mail it gets stuck in the Outbox. If you view details when sending it, you get the dreaded 80040115 can not connect to the blah blah blah. If I have them move to different machine, they log in, the mail is still sitting in the outbox, they click send, and it will send. I have installed ALL windows updates that are available and still no luck. This appears to be a Machine issue, but, that doesn't sound right.
We have just completed a migration over to Exchange 2013.
Any ideas?