Spammers, in their never ending pursuit of inbox pollution send massive quantities of unsolicited commercial emails in an attempt to coerce your purchase of something irrelevant.
Some of them even go so far as to incorporate trojans which turn your machine into a component of a 'botnet' and make your machine do their bidding without your consent.
Luckily, the internet has grown more sophisticated in it's ability to differentiate between a "exploit" and a "victim" and there are great groups tending to the effective handling of all would-be purveyors of malware and those email mechanisms utilized to effect their occult transmission.
So, in the presence of a correctly configured mail server, TLS mechanisms to ensure privacy and secure throughput, and the ubiquitous 'blacklist' to punish those indviduals churlish enough to persist ...
Why on Earth would one increase their time in purgatory by sending spam to a known agent of the army against spam and spammers internationally?
You got me but I'm knocking them out left and right these days.