Port 25 Connects, But Doesnt Respond For 30secs, [Solved]

[BizOdd]

HI Guys,
im at a loss, here. My 2 serves have been humming along for months,
server1 = Centos 4 running Xmail 1.24
server2 = Centos 5 running Xmail 1.25

Several clients called yesterday because of email delays. When
I telneted into port 25 on either server, it connects, but I dont get a
220 response for 30 seconds.
however port 110 responds instantly.

top puts the load on the machines at 0.01 - 0.11.

Ive spent hours going through the logs looking for errors or loops,
but havent spotted anything unusual.

Anyone have any ideas?

Thanks
BizOdd

>> Ive commented out the CustMapsList entry in the server.tab
>> File, and the response time is now instant on port 25.

[jonty]

Hi,

I ran into the same problem today. My server.tab file had:

"CustMapsList" "list.dsbl.org:0...."

At the dsbl.org website http://dsbl.org there is a message dated 9-Mar-2009:

"DSBL's list nameservers have continued to answer queries for 10 months after the list went off. From now on, DSBL list queries (to *.list.dsbl.org, *.multihop.dsbl.org and *.unconfirmed.dsbl.org) will go to the nonexistant nameserver stop-using-dsbl.dsbl.org, which resolves to the unroutable example IP address 192.0.2.1.
This should keep nameservers everywhere working like they should, while slowing down spam filters that are still using DSBL. Hopefully the annoyance of the slowdown will convince the remaining DSBL users to stop using DSBL. DNS timeouts should not cause any email to get lost.
Please stop using DSBL. The list has been empty for almost a year."

So I fixed my server.tab to

"CustMapsList" "zen.spamhaus.org.:1,bl.spamcop.net.:1"

And now the SMTP server of XMail is back to running normally. Hope this helps people work around this one.

Jonty

[BizOdd]

Thanks Jonty
That makes perfect sense.

regards
BizOdd