You can avoid storing mail permanently on the server, thus resulting eventually in exceeding your mailbox quota for your email account, by setting up your local email client correctly.

If using webmail we recommend you read “Deleting Mail from the Email Server: Using a Webmail client”

Outlook / Outlook Express

(1) Go into the Email Accounts section, select the email address, and then go through to the ‘Advanced’ screen

(2) Under the ‘Delivery’ section, by default, it will be set not to save any email on the server. Alternately you can set things up to save emails on the server based on certain conditions such as a specific time period in ‘days’ that mail will be kept on the server, or instead based on when you delete the email from your ‘Deleted Items’ folder.