Good point,
@Loves You, although that does end up with you continually having unread messages in your inbox. Maybe it's just me, but unread messages/reports tend to annoy me because I think I could have missed something important.
@chaoticgamer - try using your browser to log into the website version of Grepolis. Block the player there, and then just go back to using the app. Then no more worries about messages from that player.