Using Plesk 7.5.2

Say i've got an everyone@mydomain.com e-mail group setup that goes to everyone in the company, but I only want certain people to have access to be able to use it ... is that possible ?

You would want to use the mailman mailling lists to accomplish that task..

ya i set up a mailing list in mailman just using the addresses in our domain and i suddenly started going a god load of spam ... any reason for this ?

Can't really think of any good reason for that...unless you didn't set that list up properly..(ie: you left it wide-open)..but then again..a mailgroup is always wide-open...