Sandy Drobic schreef:
Koenraad Lelong wrote:
Hi, My postfix mail-server is slow to wake up. Between the setup of the tcp-connection (SYN/SYN-ACK/ACK) and the response "220 ..." there are at least 10 seconds. I (and my users) find this annoying.
Fix your dns server.
When a client connects to your mailserver, Postfix will do a reverse lookup of the client ip and a forward lookup of the result of the reverse lookup. Most probably your dns can't resolve the client ips correctly and tries until it times out.
One sign of this is that your clients are logged as "unknown" instead of the correct hostnames.
A mailserver relies heavily on DNS, correctly working DNS is a must.
It's indeed a problem of DNS, more specific the reverse DNS. The mailserver is also a slave DNS-server. This seems unable to resolve reverse dns-queries. It times out, and then the mailserver qeuries the master dns-server that answers promptly it can't find the host, which is understandable since my local users don't have dns-entries. So it boils down to : why does reverse resolving not work when forward resolving does work ? Suggestions ? I will search the net in the mean time. -- Met vriendelijke groeten, Koenraad Lelong