My domain is being abused by spammers

Miscellaneous Forums/General Discussion/My domain is being abused by spammers

Hiya, I just checked my domain hosting and there is 30GB of email which is mainly just email returned to sender :-O

Basically I only use info AT jbcomputersolutions.blah and all of the emails look like they were sent from someloadofcrap AT jbcomputersolutions. So basically I wondered a few things:

1) Can I check if my domain name is blacklisted easily? or does it not work like that, do only mail servers (mine is Wanadoo) get blacklisted?
2) How can I encode any email addresses that I put on my erbsite so that they are not picked up by bots or whatever? Forms can be abused too right? How can they be locked down?
3) If the spammer knows my domain and just uses whatever prefix, then I'm stuffed right? Or can I do something with a wildcard MX or SPF? (I don't really know what the hell those things are I just heard about them a little bit).

Any help is much appreciated. Thanx!!!