Well I'm having this problem as well and can't connect to the server. Very annoying because I have loads of stuff to do.
I looked up my IP on this site which I have never seen before and heard of in my life and it says my E-Mail provider is blacklisted in a way which has nothing to do with Minecraft
I'm also playing on a Mac and there are no virusses or trojans or anything on my machine, I also run a detailed test with an anti virus program, nothing detected. I also started to test if I have this crazy virus through Java. I don't have it and I also fixed the lack of security through Apple's Update Center.
I don't have the time to fill out useless forms on this site which I have never seen before to be removed from this blacklist. And to be honest: I don't even know what these guys are talking about on that site. I'm a programmer and have lots of stuff to do with computers but I don't know what they want from me.
Is this a plugin or something you installed for security reasons? Because I have joined several other MC servers without any problems, it's only Minetown.
Really bad to be "banned" as a staff member to be honest...