> If removing bounced messages from mailing lists in a timely manner is so
> unimportant, why did you bother to write this software in the first place?
Here's the easiest way to put bounces in perspective.
How long does a subscription address stick around before it starts
bouncing? Bad addresses usually don't make it past the confirmation
system. Good addresses are often updated properly or removed as time
goes by; even when they aren't, they usually stay good for a few years.
Let's conservatively estimate that the average lifetime is two years.
If an address goes bad, and you kick it off the list after a few weeks,
there's not much wasted mail---3% extra, plus bounces, totalling 6%.
If you keep delivering mail to the address for ten years, that's 400%
wasted mail, plus bounces, totalling 800%.
Reducing 800% to 6% is, I think, worth a bit of probing code. Bad old
addresses shouldn't stick around forever.
Put an end to unauthorized mail relaying. http://pobox.com/~djb/qmail.html