Hello,
I'm thinking about trying the example suggested in the documentation for
"sleep":
/etc/postfix/main.cf:
smtpd_client_restrictions =
sleep 1, reject_unauth_pipelining
smtpd_delay_reject = no
In general, I try to order smtpd_*_restrictions with the least costly first, so
this would be an exception. Has "sleep" shown to be:
* effective?
* cause performance issues?
* cause any delivery problems?
Or is this merely a poor-man's greylisting? Am I better off with a policy
server that can selectively implement a greylisting delay?
On a related note, is there any reason this example adds
"reject_unauth_pipelining" after "sleep"? Is using "sleep" alone with nothing
else OK? I'm using version 2.3.3, and the docs say "reject_unauth_pipelining"
is only recommended in smtpd_data_restrictions for older versions (but doesn't
say why or if it will hurt to have it anywhere else).
Thank you.
