Every now and again, I get spam delivered to my inbox from one of the leading webmail services. AFAIK, there are the big 4: Gmail, Yahoo, Hotmail and AOL.
The thing is that to my work email account where I get some of my mail (ie, I eat our own dogfood), I rarely, if ever, get spam that originated from Yahoo, Hotmail or AOL. Finding out if it came from there is easy because all I need to do is open up the message and take a look at the headers. However, I get spam from messages originating from Gmail on a regular basis.
And therein lies the rub. Across the internet, I hear quite a bit of noise that all the web services send out spam. Spammers compromise the login and send out piles of spam and then quickly jump ship and abandon the email address. However, across the blogosphere I hear that Hotmail is the worst one. The folks at Hotmail do acknowledge that there is a problem. However, I also hear that Gmail is the best filtering service.
This is simply untrue in my experience. Going by the spam I see in my inbox, when it comes to outbound originator of spam, Gmail is the worst one by far. I'm not saying that the others are necessarily better, but it certainly seems like it judging by what I'm seeing.