It would be amazing to have an option to simply check off countries you want to completely block from being able to log in to webmail, smtp, imap and pop.
If you look at the IDS blocks you can see the country (location) that was blocked for password brute force by protocol etc. which means something in smartermail is already checking the IP to a country and a 3rd party tool shouldn't be needed.
You'd still need to be able to receive email from countries if you do business in them (although having another separate option to block email from countries would be huge too [do this too please!]), but unless a client does business in a particular country, restricting login to only your native country would be a significant security upgrade to at least only worrying about brute forces that are VPN'd in to the US/Canada etc.