Hi, I will try all your advises, but something still very strange for me:
We see that postfix logs show that ehlo process is very slow through postfix but very fast by hand. Even I have recorded through tcpdump/WireShark and I can see that messages are sent very very very quickly in about 1 second.
But still messages are sent at a rate of a dozen in 10 seconds. That means that messages are sent 1 by one.
If connexion to qmail servers are slow, or if qmails are mis-parameted, too slow or anything else, When I do netstat -apn |grep :25 I get only a few connexions from postfix server to qmail servers. Even if DNS+EHLO are slow, and more, because DNS+EHLO seem to be slow, why I don't see hundreds TCP connexions ESTABLISHED ?
I expected that postfix will deliver on 30 qmail servers at the same time, and should manage hundreds parallel deliveries, hundreds parallel connexions. Is there some parameter or some conception rule that refrain him to do so?
I expected that postfix will full up his own CPU/memory creating these parallel delivery processes or/and will wait after the qmail servers, but on all servers at the same time, on multiple connections to each one.
Am I correct ? or I am dreaming of another mail transport package? Patrick
