Some messages go directly to the Deleted folder, skipping the Inbox. I'm using OWA with my Office 365 account from GoDaddy. Occasionally, a message will go directly to the Deleted folder or the Archive folder without ever going to my Inbox. Sometimes the message is marked read, sometimes it is not. Yesterday, I found a message that was from sent from the same domain/realm as my account, but a different user, was marked as read, and arrived in my Deleted folder. Two other messages were sent from another mail system and arrived in the Deleted folder but were unread. I moved the read message from Deleted folder into my Inbox. This morning, the same message is back in my Deleted folder.
I don't have any Inbox or Sweep rules set, and I can't seem to configure retention policy.