"The flip-side of filtering spam is persuading mis-configured
e-mail relays to accept mail from me. This becomes more common as
more and more clueless system administrators start collaborating
with one of the several Internet vigilante schemes out there.
Ironically, like the 'get rich quick' schemes that are one of the
stalwarts of spam, the vigilantes promise, but can't deliver.
"For me the problem is caused by certain ISPs banning
'residential' and 'dynamic' IP ranges--ranges they get from the
vigilantes' lists--from connecting to their mail servers, so that
to send e-mail to an AOL account, for example, I had, before I
addressed the issue, to send it from one of my various shell