Remote user using Outlook 2010 for PC on WIndows 7 with Exchange 2007.
When an email comes in with multiple recipients, he can reply to sender.
When he hits reply to all, he gets a message saying he needs to be connected to MS Exchange Server to complete the action.
All was working for a long time until this weekend. We did a disaster recovery drill and used SCR to move the email back and forth between servers (successfully).
His profile is set correctly.
Everyone else is working OK.