MailingManager is very easy to use, has excellent support team who are always ready with answer! I have been using this product for years now, it's constantly improving so you can be sure that no important feature will get left behind by them.
There was nothing which could not work as expected during our long cooperation - everything worked like charm :) You need an account in order to send bulk emails through their service but there should also some way how we would know when someone startsโฆ