I upgraded so I could offer this as a service, but getting clients with LEGITIMATE lists imported is impossible. Support takes weeks to get back to anyone if they respond at all. Micheal on support shows active 2 days ago but still hasn't responded to a question from March.
Sending wise its mediocre. Not as good as other mail providers and the agency aspect is useless because they never approve imports.
Save your money - utterly regret buying this pile of dung and upgrading but now outside refund window.