On Aug 12, 2010, at 10:32 AM, John R Levine wrote:
Talking out of my hat here, it is my impression that spam is much more likely
to be sent to bogus addresses than legit mail is, so however the spam
fraction of your mailstream, the spam fraction of your bounces is likely to
be even higher.
Maybe. But I've seen some *really* effective anti-spam/anti-blowback mechanisms
catch that junk and throw it on the floor at the "original sender's" side,
while still allowing "legit" bounces to go through just fine (the Ironport A/S
stuff works really, really, well, the last time I used it).
At the end of the day, though, there's an obligation to tell the sender "this
message with your address on it was undeliverable". It's up to them to filter
as they see fit. If it's truly as you say, overwhelming, they can just as
easily drop everything with FROM:<> into the bit-bucket themselves, and lose
the "5% that matter baby" along with the bathwater.
But that's THEIR decision to make, and no one else's.