You have a limited amount of storage space on the mail server. Once you reach this limit, any incoming mail will not reach your Inbox. To keep your account under quota, some occasional space management is required.
On many pages in Webmail, the quota is indicated by a small bar located just beneath the "Folders" navigation box on the left side.
It should appear as a small bar with a percentage listed in the middle.
The background color of this bar will change depending on your quota status. At 70%, the bar will turn yellow, and at 90%, the bar will turn red. At 90% quota, you will also receive an e-mail notifying you of consequences associated with exceeding your quota.
At 90% of quota, mail is withheld pending the availability of space in your Inbox. To free up space, you must delete things from the mail server.
Deleting Messages and Emptying the Trash
To delete a message, select the message as it appears in the inbox. When selected, the message line (subject, from, date, and size) should all be highlighted in one color. Just above the messages you will see a row of options. On the right side is an icon displaying a red circle with a line through it, this is the delete icon. Click the delete icon, and your selected message will be sent to the Trash. To delete more than one message at a time, simply hold the "command" key on Macs, or the "control" key on Windows while selecting multiple messages, and then click the delete icon. To delete all messages on a page, click the small dark grey square icon with a slightly smaller square inside of it, the second icon next to the "Select" header, which should appear in a grey toolbar beneath your inbox. This will select all of the messages on a page. Once all of the messages on that page are highlighted, click the delete icon. You may also delete the contents of an entire folder by clicking on the folder in the left "Folders" navigation box on the left side, and then clicking the first dark grey square icon in that same grey toolbar next to the "Select" header underneath your inbox. This should select all of the messages in that folder, and then you can click the delete icon, moving all of the messages in that folder to the Trash.
Deleting the messages simply moves them to your Trash. Items in Trash are also factored into the quota. To free up space, you must delete the messages permanently by emptying your trash. To do this, manually select all the messages in your trash folder, or press the first dark square grey icon in the grey toolbar underneath the inbox (selecting all messages), and then press the delete icon in the Webmail toolbar. This deletes all of the messages from the Trash.
Webmail offers easy ways to download your messages to your computer before deleting them. Note that when you download a message and then delete the copy on the server, it will no longer be accessible via Webmail.
To download a single message, open it in Webmail by clicking on the subject. Then click the Gear icon in the right side of the Webmail toolbar. It should open a dropdown menu, with one of the options being "Download." Click this and save the file to your preferred directory on your computer.
Reading Downlaoded Messages
To read a downloaded message, open the .eml file of the message with Thunderbird. You will be able to read the message, but it will not be stored in your inbox in Thunderbird.
Deleting Attachments From Saved Messages
Getting rid of large attachments can allow you to keep important message text while greatly reducing the amount of space the message takes up. When you open a message with an attachment, you will see a small red circle with a line through it, a smaller version of the delete icon, next to the attachment in the message. Click this to delete the attachment only.