Vintinner, M. Scott wrote:
One of our very important clients (a major bank), is having ongoing
problems with denial-of-service style dictionary SPAM attacks. Their
anti-spam/firewall teams are slow to respond to these outbreaks, so
there may be periods of several hours where we will get frequent
connection refused messages as their resources are overloaded.
As you know, the "cool-off" period in Postfix extends the retry delay of
messages in the deferred queue from an initial time of
$minimal_backoff_time to the maximum of $maximal_back_off time. So with
the default configuration, my postfix server would try to deliver the
message at 0/300/600/1200/2400, and eventually only trying every 4000
seconds (~66 min).
. . .
Am I understanding these settings properly or should I be trying
something else?
I've toyed around with adjusting the maximal_backoff_time globally to
300s, but it bugs me to see retries on messages sent to yaho.com and
hotmial.com.
What does your log say when you try to deliver a message and it fails?
Terry
