Sender gets a "Mailbox Full" message

If people sending to your email account receive an error stating Mailbox Full or if you try to send a message and receive this error, you may be out of mailbox space on your account.  Try the following:

• If you have SmarterMail, see this Full Mailbox KB article.
• G Suite users -> see how to Clear drive space and increase storage.
• If you have another email system, you could find ways to clean up your mailbox. For example:
  • Delete unneeded messages from your Inbox.
  • Empty your Trash.
  • Find messages with large attachments (for example, ones with pictures) and save them to your hard drive before deleting.