[dijit]

>look how nice Greylisting worked in theory, until you realize that most IT or hosting companies don't have a clue how to configure an MTA within RFC specs and do silly things like retrying delivery every 5 mins.

that's what needs to happen for greylisting to work.

it's spambots that don't have the retry ability.

[RawInfoSec]

Thanks, but you misunderstand my point. Actually you pretty much prove my point that most MTAs are run by those who can't grasp that there are RFC standards out there.

An MTA should never resend after only 5 minutes. It should wait at least 25 minutes before even the first retry.

I've seen many set up to retry every 60 seconds, giving up after 5 tries. One IT tech even told me it was so his boss doesn't have to wait 3 days to get a non-delivery report! Lol.