[CentOS] slow sendmail going out

Wed Apr 27 16:33:42 UTC 2011
Gregory P. Ennis <PoMec at PoMec.Net>

0400

I am trying to find a way to "speed" up sendmail going out of my box.

I am setting SMART_HOST. Dont get me wrong email does go out it just takes
like 3-4 minutes to get there.

When I do "mail xxxx at y.com" and send it the /var/log/maillog file shows
the connection and shows the relay as [127.0.0.1]. Then it just SITS 
there for a long time.

Then it picks up the mail and delivers it. No errors are show, no 
timeouts etc...

My box does not have an MX record as  I am behind the firewall 
(192.168.1.X).

I have set the /etc/sysconfig/sendmail QUEUE=1m but that does not seem 
to help either.

There is nothing else happening on my box so that is not slowing 
anything down.

I've done some google'ing, some playing and nothing has helped. I tried 
adding the service.switch
to sendmail.mc, I tried temporarily taking out dns from nsswitch.conf - 
and nothing seemed to help.

How can I get emails exiting my box faster.

Jerry
----------------

Jerry,

I had the same problem with sendmail.  My solution occurred when I set
up DNS resolution internally.   I had a lot of 'time out' conditions
when dns resolution was not obtainable with sendmail.  Having a name
server with reverse resolution totally solved this for me.

Greg