Hi @ramin sa ,
one of user mailbox says items in favorite in OWA 2013 disappear and only item in inbox show to me
By this, do you mean only Inbox folder appears in the Favorite section now, while the other folders this user added to Favorite previously all disappeared?
If this describes the situation and this only occurs to the particular user, it's likely that the missing folders were removed from Favorite by accident and it's suggested to adding them back by right-clicking the folder under your personal folder, and select Add to Favorites.
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