ToolBox -

The most common cause of this error message is people trying to login to the webmail application using their email address/alias rather than their mailbox account number.

 

Image showing the direct webmail login (use only mailbox account number followed by @manxbroadband.com)

To login using your email address go to https://secure.wimanx.com/webmail/

 

Image showing the preferred portal to login to your email using your email address/alias