I have a different problem. I got a message and when I clicked the read button I got a page saying I was trying to access content that had been removed. I clicked on the sender`s username and the same happened. Consequently, I sent him a PM to find out whether he had sent anything or not. I got a "reply" - the PM I had sent. And both PMs disappeared later on. This site is hounted. 

Lost message
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I may be going crazy, but I thought I sent a message to someone yesterday but it doesn't show anything being sent in my 'sent mail'...anyone else have this issue?