There are several setting and configuration to set your SMTP authentification:

1. SMTP through PHP web server

2. Outlook Express

What information that I need?

SMTP Hostname
If you've been asked by your email software your SMTP hostname, you can fill it with :

Hostname: mail.yourdomain.com
Port : 25 (by default)
Username : (your email , you must add new email in your cPanel first)
Password : (your email password)

If your ISP don't allow port 25 to be your smtp port, please try port : 26 instead.
You will need to try port 26 while you can't connect to your ISP smtp port that directly to our email server.

For outlook express , you can try test account setting after you fill in all smtp information above.

If you need to enable smtp authentification via PHP script, the default connection was port 25 with the hostname and smtp authentification that already display above.

For Web Developer:

Please do your smtp email connection setting correctly and set your header with fully configuration, so that it would overcome your email received not in bulk mail or junk mail as the destination. It also for sendmail php function with mail(), you need to set full email from and header to prevent email received in bulkmail.

If you have further question, please contact us, visit http://www.techindo.net