First some basic info:
I have a user that accesses contacts through a company share email account (as opposed to keeping contacts under his own account). Recently, the hosted email accounts were with AppRiver (hosted Exchange) and switched to 365, still through AppRiver -- After setting up the new profile, this problem cropped up.
If you look under "People" in the shared contacts, everything displays properly, i.e. name, phone, email address, etc. All functions work from within each contact. However, if he starts a new email, and clicks the "To..." button, the contacts will display, but the email address column is blank (for almost all contacts, except apparently newer ones). It will allow you to select a contact as your recipient, but when you hit send on the email, it comes up with the error: "The operation failed. The messaging interfaces have returned and unknown error. If the problem persists, restart Outlook. Cannot resolve recipient".
I realized quickly that it was not pulling over the email address and therefore doesn't know where to send the email, but I cannot figure out why, or if there's anything that can be done to fix this. I tested making a new contact, and that does work normally, but the existing contacts (upwards of 2,500) are not working, so re-creating them is obviously not a realistic option.
Any help or ideas would be greatly appreciated!