Emails received with "Mailbox Size Warning for accounts that the user owns." in the heading

Yes those emails are legitimate and tell you that your mail box (on the server) is reaching it's quota. Most emails accounts have a quota of 250 MB and once the quota is reached you will have difficulty sending and receiving emails

This usually happens when a setting on your email program on your computer is not set correctly (there is a setting in "server settings" that allows you to delete emails from the server after downloading. This must be set to "on" (in other words, the box must be ticked)

You can make adjustments to your email account by going to your control panel "your-domain-name.com:2082" and logging in using your credentials and then, navigating from Home, scroll down to "Email" and look for "Email Disk Usage". Click on that icon and where it says "Account:", pick your email address you wish to adjust. You are able to manage each folder by clicking on the "manage" link on the right hand side.

You can also check what emails are sitting on the server by going to "your-domain-name.com/webmail/"  and logging in using your email address and password for that email address and navigating to your Inbox.

You will easily see what emails you have read and those you haven't

You can then go back to the control panel (as above) and adjust the emails easily from there.

Please note. The log in details for the control panel are the credentials sent to you when the account was set up and are different to the Webmail log in details which are the email address and password of that email address.

If you need further assistance, please submit a Ticket and we will assist you