When you configure your mailclient with POP your emails would be downloaded to your device. If you delete them locally that action will not take effect on the server. Some mail clients and apps will keep all messages on the server, some will delete them as soon as the messages are downloaded on your device, and some will give you the option to choose during configuration.
If you have kept a copy of all your messages on the server, at some point it will fill in completely.
Mailbox full? Delete e-mails directly via webmail
Follow these steps in Webmail
- When you are already in your inbox, choose the message you would like to delete. If you want to choose multiple messages, click on the first message and hold the Shift button while pressing the down arrow on your keyboard.
- Navigate to the top and click on “Delete”.
- The messages are already deleted.
Enable the feature that will delete the selected message immediately instead of moving them to the trash folder. This is very useful in case that your mailbox folder is full. Go to “Settings” > “Server Settings” > Click on the slider next to “If moving messages to Trash fails, delete them” to enable the option and click on “Save”.