Mailbox is Full

Error:  You get a message telling you your Mailbox is full.

This error says exactly what it means, your mailbox on the server has run out of space. The thing is, if you have your email accounts configured correctly on your PC/phone/tablet and one of them is set to clear the mailbox then the message is just a warning and the mailbox will have cleared when you have completed the mail download.  But if you haven't then you are not going to get any more email in until it is cleared.

Check:  Is your mail configured as a POP or IMAP account? (Note: see the Blog article IMAP vs POP for more information)

If you have multiple devices checking mail then it depends on whether you have set them up as IMAP or POP accounts to determine if you can actually clear the mailbox. IMAP and POP accounts are what you setup on your phone/PC/tablet when you want to collect yoru mail.

IMAP accounts

If it's an IMAP account then you can't clear the mailbox unless you delete all your messages (and then purge them) on the device you are reading the mail from.  IMAP synchronises to the server mailbox so if the mailbox is full you need to clear some mail on your device which then clears some capacity on the server. The alternative is to create a local folder on your computer/phone instead of on the server, and theno archive messages from the server into it. This will reduce the disk-space used by your e-mail account on the server and help it remain small.  That way the sync works faster as well.  You really need IMAP mailboxes to be small to maximise their efficiency.

POP accounts

POP accounts can be set to remove the "read" messages from the server immediately they are downloaded or after specific conditions are met. If reading your mail from several devices, one of the must be set to delete the messages otherwise you will never clear the mailbox.

Use Webmail to manage your mail.

You can log directly onto the server via Webmail and manage your email via one of the 3 optional online email programs.  These display the contents of the mailbox directly so you can delete those messages you don't need via this system.  Webmail is accessible via your web browser at the URL  http://(yourdomainname)/webmail, then just enter your email address and password.