Newbie has a limit of PM that he/she can send on daily basis but a lot of people have blocked Newbie Message them in the "Personal Message Options".
Your account will not get suspended on this basis but if you advertise anything illegal then people can report you and your account can be subject to tag.
Its better if you can advertise here on the forum publicly rather then PM to people. Those who are interested in your services, will contact you themselves.