Setting up Pegasus Mail:

Select Tools · · > Options
Select the Network tab
In the box:
 

 Fill in the correct information as indicated below:

Your email address is: yourname@yourdomain.com
POP Host: yourdomain.com
User name: The name of the POP account.
POP account password: POP password
SMTP Host: Enter you ISP's SMTP server.
 

 Next, select the Advanced Network Configuration button:

Make sure that the Delete mail from host once successfully retrieved box is checked, Click OK.
 

 Finally, select the General tab and enter the following:

Personal name: Enter your real name.