The total allowed space over any single mail account is 100MB. If your total exceeds this amount then your account is full and emails must be deleted to downloaded to make space for new ones.
There are two options for this scenario;
- You can log into webmail and delete emails directly from the server/webmail. This may be time consuming if you have thousands of spam emails.
- If these emails are just duplicates of what you have already downloaded to an email programme on your computer, then you can simply delete the account from your admin panel. Wait 5 minutes until all emails are deleted, then create the account again. Be careful, the password you enter when creating the account must match the one in the settings of your email programme used to download mail to your computer.