Very slow sendmail greeting

[Morris Jones]

Hi ...

My friend and I have set up SMTP backups for each others machines, Linux
machines running the latest sendmail (8.9.3).  We have domains set up
and working well.

As I was testing our mail relaying, I noticed that sendmail was taking
a very long time to answer a connect to port 25 with an SMTP greeting,
about 30 seconds.  This was true on my machine and his.

The obvious culprit is that sendmail is timing out on a DNS lookup,
but the reverse and forward DNS for my test machine at work is fine
and has a quick response.  That doesn't seem to be it.  It also has
the same slow response from his machine to mine and vice versa.

Could there be something in our local configuration causing extremely
slow SMTP greetings by sendmail?

Regards,
Mojo
-- 
Morris Jones         <*>
Campbell, CA
mojo at whiteoaks.com
http://www.whiteoaks.com