Any email client on your computer usually requires the following settings when adding an email account.

Just subsititute your emailaddress domain name with "yourdomainname" below. 

POP3: mail.yourdomainname.com

   -  This is the address for incoming email or where you receive email from.  It runs on the standard POP3 port of 110.
 

 USERNAME:  This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

    -  This is your full email address you use to check the email online or whatever email accoutn was setup.  If you setup a email alias like This e-mail address is being protected from spam bots, you need JavaScript enabled to view it to point to your email account, you must use the master account as the Username.  Email aliases are only a way to forward the mail, not access the server.

PASSWORD:  <your password for your email account>

SMTP: mail.yourdomain.com    (READ BELOW)

     - This address is how your email client SENDS email out, or the outgoing server address.  It runs on the standard port 25 and also port 26.  The majority of Internet Service Providers are now blocking the use of any SMTP server other then their own in a fight against spam.  This means that you cannot access this server to send email through and MUST follow your Internet Service Providers method of sending email.  Usually they have their own SMTP settings.  If you really want to use our email servers to send email, you can try going into your advanced settings and change the SMTP server port to 26 to see if that works.  In some cases this is blocked as well.  The easiest method is just to use the same SMTP server for all your email which would be your internet service provider.