Neither potential clients nor current clients are expecting a newsletter from the company.

So the company would need to somehow invite them to sign up for that list. Importing their list into MailChimp w/out their permission, then sending them all a mass email, would technically be violating our terms of use since they didn’t opt-in (yet).

And since managing contacts inside Outlook is fraught with so many problems, the safest thing for them to do would be to use Outlook to individually contact each client/potential client and invite them to join their new list.

When I say “invite them” I don’t just mean send them some link to go and sign up.

Some creative incentive would be in order. A giveaway, a useful research paper, etc. This is actually the hardest strategic part of email marketing. It’s hard work coming up with the value that would make people actually want to sign up.

http://blog.mailchimp.com/loyalty-before-frequency/

After you clear that hurdle, the rest is just “saying useful stuff on a semi-regular basis to people who want to hear from you.”