There is always a big debate between Aweber and Getresponse. I use Getresponse because they are a bit cheaper and I haven't had any problems with them. Aweber is used by most of the Guru's so that's gotta tell you something. Cheers
I've used www.constantcontact.com before. The only problem with them is that if someone complains of spam more than 1 time per 1,000 emails sent...they can ban your account no questions asked. If you want to try a free software you install yourself there is one called PHP List. Nothing fancy though.
serch "sendmail", it is a program that sends email for you for free.. you need your owner server and a bit programming though.. you can use the email SMTP service offered by your ISP for free just fine..
I would not use any free service. I have used AWeber for many years. They are awesome and very good customer support. - Jens