Now and then a spammer registers on the forum and posts spam messages, some of them quite offensive.
We check the forum frequently and remove such spam postings, also banning from the forum the registered spammer.
I would like to consign spammers to the most unpleasant region of Dante’s Inferno. Some of them seem to have developed automated means of registering on forums and posting messages.
This has made it necessary to ban certain email addresses that are often used by spammers. That includes Hotmail, Gmail and others. We recognize that this causes problems to some users. But each time we open banned email hosting addresses the spammers strike.
We want to apologize to our user community each time a spam post appears on this forum. At best they are off-topic and are a waste of time to read. At worst, some of them are very offensive.
Over the past several months we have caught and removed at least a thousand phony registrants whose only purpose in registering was to spam the forum. The developers have made some changes to the registration process that seems to have reduced the problem, but we still have to monitor the forum frequently.
For the low, low price of $450 dollars one can buy a software package that allows the user to automatically register and post spam on more than 102,000 Internet forum sites (including this one). That package limits the user to only 10,000 posts, but for more money there are higher priced packages increasing the number of possible postings. 
The dolts who buy such software and flood forums with spam are typically responding to “home business opportunity” advertisements that promise six-figure incomes without actually having to do any work. Most of them will be out hundreds or thousands of dollars and will never recover their investment in that wonderful opportunity.
By contrast, most of our user community are either professionals who have gone through years of career training, or are in the process of getting such training. IMHO your investment of time and money in your career will be much more rewarding, and you are much more likely to make productive contributions to the world than are spammers.