Mailpoet offer a secure alternative to others

Supporting many non-profit associations we see the need for intra-association communication. Mailpoet offers these organisations the ability to build quick and easy communications with their members and maintain control over the contact details of the subscribers.
Unlike a cloud service, the information that identified the subscribers is kept within the Organisations domain and not handed off to a third part as in the case of Constant Contact or Mail-Chimp.
This is important when privacy of the contact information is demanded.
Mail poet offers many facets that are available in these other services and the premium version gives the ability to track and analyse the mailing in very minute detail, allowing the users to quickly and simply adjust any email marketing campaigns.

Excellent product with great support.