There may be times when an Inbox can be come overloaded with messages. If you are receiving large amounts of SPAM and have not set up SpamAssassin and filtering, or haven't organized your emails into folders you may find yourself with an Inbox that is virtually overflowing. This can cause issues when trying to open your Inbox in Webmail or when trying to connect to your account with an email client.
If your Inbox has become too full and you want to delete all of the email messages in your Inbox, you can use one of the three Webmail options to clear out the emails, or as a last resort, use the cPanel File Manger to delete messages.
Please note, the instructions will walk you through deleting all emails in your Inbox. If you have any emails in your Inbox that you wish to keep, you will want to move them into a separate folder first.
If you have messages you want to move to another folder that, you can also create filters within the Horde Webmail client and run the filters on messages already delivered to your Inbox. You can set up filters to move messages based on any number of variables such as the sender's email address, the subject line, etc. Please note, you would need to set up the filters within Horde, as it has a separate interface for these filters than the ones that can be created in cPanel.
Once you are ready to empty your Inbox, please follow the instructions in one of the following articles:
Mass Delete Emails in Horde
Mass Delete Emails in Roundcube
Mass Delete Emails in SquirrelMail
Mass Delete Emails with cPanel File Manager