Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
So, yeah, drain bamaged anti-spam ... I recall many moons ago, Rick Moen sent an email which had a http or https url which ended in linuxmafia.com ... probably just https://linuxmafia.com Well, silly rules in eximconfig would look at that and essentially says, oh my gosh, that's a URL to a .COM executable file, must protect those happless Microsoft Windows/DOS users from that, and can't allow that thorough, it's probably some malware binary anyway. Well, anyway, at this point shouldn't be getting tripped up by stuff like that.
Well, what can I say? EximConfig (no longer maintained and too crufty to even be a reasonable point of departure, any more) was in its heyday a large and varied grab-bag of Exim and other rulesets that were aggressive and effective with low system load -- and pioneered innovative spam-evading techniques such as SMTP callouts/callbacks to the delivering IP during the SMTP conversation to check RFC compliance.
It was always the case, however, that occasionally you would find that some of the ruleset entries were overaggressive and unwise, so you would comment those few out as you found them.
Pretty soon, I'm going to pick your brain on some parts of modern Postfix antispam setup -- assuming you're current on that. I'm fond of exim4, but am thinking it might finally be the right time to bail. Not decided on that. I might instead pick your brain on some parts of modern exim4 antispam setup.