Just about to send out an email to just over 1000 people. Technically what is the best way to go about it? Do you write your own code or do you use sofware? If so what and is there any good free sofware that you could suggest?

Thanks

I hope they are all opt-in e-mails.

I am looking at using Anconia RocketSales to run some opt-in e-mail campaigns soon.

When does a mass mailing become a spam. I am interested in targeting specific groups for a service. If I cannot mail them, how do I tell them about myself.

mass mailing becomes spam when advertising by email to people who did not ask to receive the email. What exactly are you promoting? Try using search engine listings.