Rafael Azevedo: > Hi Wietse, > > I thing I havent made myself clear. > > I have an email app running on BOX A and POSTFIX on BOX B. > > The BOX A connects to POSTFIX to send the messages. > Thats exactly where the delay is. When the application tries to send > the messages to POSTFIX, the APP sends about 2 messages per second TO > POSTFIX using domain ZOOM4U.COM.BR.
> The bottleneck is when POSTFIX RECEIVES THE CONNECTION from my > application when using domain ZOOM4U.COM.BR. There are no "fast" or "slow" domain names in your logging. Therefore, your conclusions are not supported by your evidence. What I do see is that your server can't deliver mail due to DNS lookup error (50% likelihood of NXDOMAIN). Delays while delivering mail will result in delays while Postfix receives mail. This is a built-in defense to prevent the sender from overwhelming the Postfix queue. Therefore, you need to fix the delays with mail delivery (due ti bad DNS or whatever). Then, there will be no delays while Postfix receives mail. Wietse