The issue is in connection with sendmail service taking too much time at boot up.

I've been told that it's a DNS issue, my hosts file looks like below;

127.0.0.1 localhost
192.168.10.3 optiplex

The second entry is the machine itself, if I have the second entry, sendmail freezes and if I don't, httpd fails and gives me the following error;

"httpd: Could not determine server's fully qualified domain name, using 127.0.0.1 for ServerName" [FAILED]

What am I missing, or what should I do to have httpd run properly.

Also, when I have the second entry, I still get the above error message with 192.168.10.3 instead of 127.0.0.1 but httpd still runs.

So I believe I have something wrong setup that's causing httpd service to generate that error message and for sendmail to freeze momentarily.

Any help is appreciated.

you should set the ServerName variable in your httpd.conf, usually one sets it to ones FQDN
you in your case optiplex.yourdomain.com

check your sendmail logs, and see if anything is wrong, cuz from your information it just look like it's taking a while to resolve the host name.
adding your host name to the first line you posted might help

Well, sendmail has nothing to do with httpd failing so didn't expect sendmail questions when reading your title.

It might also help to possibly change your actual machines hostname and assign it to a domain as well, instead of using probably the default localhost and localdomain.

And I'm assuming you don't have a domain name for this machine, one that you've registered, etc? What's your intention of running these services?

I got it fixed, it was just wrong entry in hosts file, it's all working now.