Only admins can can see private messages, or mods too? Or for mods to see the PM, it has to be reported? I am asking so at least we can confirm that PM is legit and indeed sent by Ampth (even though I see no reason why Lucius would go through such hassle).
Global moderators, and admins can see it when reported. If you go, and look at a personal message you've received, and click report to moderator you'll be able to see who can review them, since you can pick who you want. However, admins can probably see any personal message if they wanted too, but this certainly isn't routinely done. Although, this falls out of the scope for them to verify since it's not breaking the rules of the forum. So, please no one report personal messages like this, only one's that break the forum guidelines. There are other ways to verify it, obviously. In the past, some users have given temporary access to trustworthy users, but I wouldn't recommend that either.
