Two IBM Notes users at our company send meeting invitations to a gentleman at an outside company using Microsoft Outlook to Office 365.
The gentleman is able to process meeting requests from one user but not another.
The user who sends the meeting invitation which cannot be processed has NO local contacts (which rather stuns me). But did have this person in their recent contacts. I deleted all recent contacts and told it to stop storing people in recent contacts.
They sent out another meeting invitation. waiting on the results…
Hate to give you a partial post. At best this may be a lead for someone who runs into this in the future.