This situation can be due to many different causes. So it's impossible to give a 100% precise answer. Still, review these situations:
- Does your email account have available space?
- You can see the assigned space in the email section of your control panel.
- Are you using the correct incoming server?
- Make sure you follow the instructions for incoming and outgoing servers
- Are you using the correct password?
- Is the username correct?
- Remember that your username to read your email is always your email address
- Are you using the correct port?
- Port information can be found here: /en/support/email/setup/email-reading-ports/
Try to verify each of the above questions and open a ticket answering them and including the error shown by the email program you use. One of our technicians will help you resolve your problem.