Yes, I run a mailserver. I can confirm spammers use all sorts of techniques in order to send SPAM. They have spiders crawling the web and create e-mail addresses out of words you use on forums, plus dictionary.

Say my e-mail is e-person@mysite.com, then I write a message about istock and microstock, they will try to send messages to:

e-person@mysite.com
microstocke-person@mysite.com
microstock-e-person@mysite.com
istocke-person@mysite.com

And so on.

I can't exclude that these public domain softwares used to run these forums contain backdoors, tough.