Newsletters - removing subscribers

Currently I am with aweber for newsletter services.

I have 40 follow up emails which I send to subscribers over a period of 6 months. After 6 months are over I would want to remove subscribers older than 6 months. Aweber is not allowing to remove subscribers and charging based on subscriber count. After a while I will be paying huge to aweber unnecessarily for subscribers who are not contacted and who might not cause a sale

Anybody please recommend a email service like aweber and constant contact who allow this feature of removing subscribers from a list.

Campaign Monitor allows you to do that

Disclaimer: I am not, nor was I ever, an employee, parter or affiliated in any otherway with this company.

http://www.aweber.com/faq/questions/61/How+Do+I+Unsubscribe+Someone+From+My+List+Manually%3F

Aweber certainly allows you to remove subscribers from your lists.