Add/Delete subscribers for a newsletter on a existing website and automatically update our software program

There is an already existing website, [[login to view URL]][1] and we want users to be able to subscribe/unsubscribe for our newsletter. When they visit the website, there should be probably like a checkbox on the first page where they can enter their email and accept. When a user wants to unsubscribe from the newsletter, he should be able to do this also on our website, so a subpage on our website should be created where he can enter his email address and receive an un-subscription verification. Obviously we want to be able to watch, check and manyally export these entries but the most important issue is that a table with these entries (new subscriptions or un-subscriptions) will be automatically sent (by a everyday routine task) to a programm we use based in Delphi. At the end of the project, we require a 30-day technical support to verify that everything works as agreed and solve any possible issues that may arise.