Office 365 delivered the message to the recipient. After delivery, the mail was moved to another folder. Search the {FolderName} ...

Office 365 delivered the message to the recipient. After delivery, the mail was moved to another folder. Search the {FolderName} folder of the recipient to see if the message is still there. If you can't find the message, try disabling Conversation mode when performing your search.

If the message still can't be found, the message may have been accidentally deleted or moved to another folder. Therefore, a search of the recipient's mailbox for the message may locate it.