Mailing List software selection

We need an emailing system selected which is suitable for a Wordpress website. The system needs to include registration form, thank you page in the same style as the registration form, triggers for the registration form, email delivery with customised templates, and post delivery reporting. The various parts of the system can be from different plugins or sources as long as they all work together. The software needs to be licenced for 1 to 5 websites. No monthly or ongoing services are wanted, the system should be comprised of elements which are fully purchased or free. You review and advice on the various options is required. Another project will be created to implement the selected system of components. In your bid please provide explanation of your specific experience and skills in this area. Thank you