Basically I need something that simply holds emails and sends emails, that is easy to work with....think something like Groupon, where you go to their site and enter your email, then you receive certain emails when they decide to send them. I've heard of Sendgrid and Mailchimp...and I've been told that places like Groupon use ExactTarget. Do any of these sound familiar? Which would you use?
There are already many other threads discussing the various email marketing services, try searching them for more information. MailChimp is not an option if you do any kind of affiliate marketing, because their ToS forbids it. Generally, the best known email marketing services are Aweber and Get Response. But, if your are looking for a quality free service, then check out List Wire also.