Check your Configuration
The first thing to do is verify that you have configured your e-mail client correctly.
At the very least, make sure that you have your
POP (Incoming) Mail Server set to
yourdomain.com is your actual domain name.) Do not prefix your domain name with
pop3. or any other prefix.
Also verify that your username and password have been entered correctly. For the e-mail account
email@example.com, the correct username is:
yourdomain — it is not
yourdomain.com. Read more