mouss wrote:
Sorry for being dumb, but what are FPs?
False Positive. in spam filtering context, an FP is when your filter
mis-classifies a legitimate message as spam.
It's also beneficial for true positives (semantic argument about what
constitutes a "false" positive avoided). If you're the email admin for
any number of domains, I can basically guarantee that you will receive
the following phone call at some point:
"Hi. My brother from Tennessee was supposed to email me some photos of
his new koala bear and he says that he sent them but I never received
any cute koalas. HOW COME EMAIL IS BROKEN THIS IS IMPORTANT."
With smtpd_delay_reject=yes, you can just grep your mail logs for
'sen...@example.com', and you will see that the user's brother (for
example) has been listed in zen.spamhaus.org for sending his photos to
the wrong people. This at least allows you to claim that it's not your
fault without having to lie, and in many cases, you can even fix the
problem.
With smtpd_delay_reject=no, you're in trouble. You have to try to guess
from which IP address mail for the sender's domain originates. Good
luck. Only then can you begin to search for the cause of the problem.
And, if you don't find any logs mentioning that IP address, there's
always the possibility that you guessed wrong anyway.
