Hi,
I’ve 2 servers in 7.02 in a clsuter with SMTP running. When I telnet on port 25 from one server to the other, it takes around 20 to 30 seconds to have the response 220…
When I telnet from outside the network it is the same.
When I telnet from one of the both servers to a SMTP on the internet the response is immediate.
I didn’t find any parameters to set timeout or something like that
Can someone help me please ?
Thanks
Regards
Subject: Telnet to SMTP takes long time to get response
Hi JP
Just a guess but what makes me suspicious is the delay for ANY incoming telnet command… directly and from outside your network ?
Any chance that there is some firewall or other device doing portfiltering on 25 ? That might explain the delayed response only for incoming.
HTH
Stefan
Subject: Telnet to SMTP takes long time to get response
did you ever resolve this one?
I’m currently researching a similar situation at a customer site.
The symptoms remind me of something I’ve seen back in the ‘good old R5 days’ where domino on windows with multiple NIC’s, where not all NICs had a DNS server defined, would have smtp delays.
DNS lookups (forward AND reverse) from the server console (nslookup) worked fine.
Back then I added an entry for a DNS server to one of the interfaces that didn’t have one at the time, which fixed the problem.
right now I’m waiting for a change to be implemented at the customer site to see if this will fix the problem.
Cheers.
IRC: Woonjas on EFNet’s notes
Subject: check reverse DNS and DNSBL (blacklist) configuration
Turned out to be a combination of not working reverse DNS resolution (amounts to approx 5 seconds delay), for both the host itself as the connecting host and an entry in the DNS blacklist configuration that no longer exists (relays.orbs.org, which amounted to approx 10-15 seconds).
P.S. relays.orbs.org has ceased operations about a year ago, if you still have it listed, remove it.
Subject: Telnet to SMTP takes long time to get response
Make sure your servers have valid reverse DNS entries for IP their addresses; that’s usually what causes a delay before the initial SMTP greeting. On Unix it’s 60 seconds, and the usual response to generic “xxx takes exactly 60 seconds to start” complaints is “fix your reverse DNS” 
Not sure what Windows’ timeout is.
(update) Erp. I noticed you said that connecting to remote servers from those machines is fast, so that indicates your reverse DNS works at least from outside. Maybe start up Wireshark and see if you can determine what the server is doing during the delay?
Subject: RE: Telnet to SMTP takes long time to get response
Hi thanks for answers.
To continue, It seems that the problem is only with 7.0x domino servers.
Telnet to 6.5x server is faster and answer immediate wherever servers are located (on my lan or my wan).
I keep on investigate…
Subject: RE: Telnet to SMTP takes long time to get response
Keep looking into DNS resolution or an inability to contact one of your DNS servers. I just experience the same problem/delays for incoming and outgoing connections. I was missing some connectivity to one of my DNS servers. Fixing this brought this back up to speed!
Try doing some DNS lookups from the server having the problem. You could also try to verify connectivity to each DNS server you use by a ‘telnet servername 53’ and see if you get a response back.
Rich