Welcome to Horde.

Aktivix users have received emails with those words on the subject line, then this:

This is to notify you that you are over your mailbox limit which is 250MB as set by your mailbox manager, you are currently at 257MB, you will not be able to create new e-mail to send or receive messages until you validate your mailbox. To re-validate your account:LOGIN TO OUR MESSAGE CENTRE
Help Desk

And with a link to some obscure link.

These emails are scam. If you click on that link, whatever details you are giving, and whatever details your computer will be giving without your knowledge necessarily, will reach some unknown company that operates for a profit most probably selling those details you’re providing.

So don’t do it.

Aktivix will never send you such an email asking you to log in somewhere to provide your details.

For more info you can ask publicly on the discuss list or more privately on the request list; check http://aktivix.org