On 2011-09-01 at 11:05 -0700, Jeff Lasman wrote:
> # Accept hosts who are polite enough to wait rather than just send, as spammers do
> accept hosts = *
> delay = 3s
> Is there a community concensus on whether or no this is reasonable?
This is email. There's no community consensus on _anything_.
That said, I am one of those who does a delay, to expose the protocol
pumpers which don't synchronise correctly.
Make sure to whitelist your monitoring system. It's also handy to
whitelist all IPs configured on this host: @[]
What I do reduces down to:
acl_connect:
accept hosts = @[] : +remote_hosts_nodelay
warn set acl_c_delay = 0
# ...
warn set acl_c_delay = ${eval10:3+$acl_c_delay}
# add 2 seconds if on an RBL, etc etc
# No delays at connect for submission, it's in the user-path:
accept condition = ${if =={$received_port}{587}}
accept hosts = *
delay = ${acl_c_delay}s
together with a hostlist "remote_hosts_nodelay" which includes
+relay_from_hosts. The real ACL is more complex than that, because
that's how I roll.
Arguably, you might use a DNS reputation whitelist to reset the delay
down to zero before the end there.
You'll probably want to end up whitelisting the high-volume senders you
trust, if you want to keep them happy.
-Phil
