Weird issue. Users log into their normal windows account. As they move from site to site, they log into Outlook to a Shared Mailbox. If Users 1, 2, 3, 4 decide to login in to the shared mailbox it works fine. When the Shared Mailbox and AD account is disabled (when a site closes) it also disables all the users who have previously connected to it too. Any ideas? Thanks in advance.
Can you tell me some details information about your environment?
Did you check the event viewer and find some error messages?
I found an article about shared mailbox for your reference.