When you say, "My question is - How many can I send before I am being labeled as a spammer :-)"

Do you mean:

a) How many can I send before I am being labeled as a spammer by the people who are receiving the emails?

OR

b) How many can I send before I am being labeled as a spammer by the anti-spam filters on mail server?

Most responses so far are to (a), but I'm guessing you might mean (b)..?