If you have a blog and also in wordpress then you can get free plugins, if not then there is no chance of getting it free.
Those emails are indeed sent by bots, but they are not just "for fun" or "to annoy website owners".
Rather, they are "testing the waters". If you look at the content, they are trying to insert links in various ways. The bots don't know that the comments are going to you rather than being posted on your page. They are trying to insert links in comments on your pages. If they detect a successful method (by coming back later and looking for the same nonsense that they tried to insert), then they will start spamming the crap out of you.
They normally have large casino / herbal-supplement / porn operations behind them.
Contact Form - PHP Development
Another solution is to send all the email to a gmail account and some of the spam will be filtered out.
Sami4u (29 October, 2009)
Submit new proxies -
Sami, if that is your real e-mail address in the PHP code that you posted, I would remove it immediately. Spam also bots read NB.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin
Sami4u (9 November, 2009)
Sami4u (10 November, 2009)