Sendmail not working on CentOS

I have a CentOS server configured with sendmail and none of my messages seem to be sent.

I am looking at the maillog fiel and see this error "Jul 16 13:38:43 fmsubbnix sendmail[1140]: n6GHcgRE001026: n6GHchRE001140: DSN: Host unknown (Name server: host not found)"

My guess is the the parameter "Name server:" is incorrectly configured.   I probably need to use the company's smtp relay server.  Where is this value located?

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

can this server resolv external host ?

smart host , option would be on


look for smart host options in their , and use company smtp server

define(`SMART_HOST', `smtp.your.provider')dnl

dont forget to run


then restart sendmail

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
gordonmannAuthor Commented:
Please define "dont forget to run make"

if you change any sendmail configuration

you need to execute make command

just type


then restart  sendmail
gordonmannAuthor Commented:
Great -- Thanks
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Email Servers

From novice to tech pro — start learning today.