Nick,
Easy way is to subscribe to Mailchimp which is free for relatively small lists and does not take long to learn. Their product will do mostly what you want plus a whole lot more, but note that while it is easy to have a personalised Dear xxx, personalising the subject line is more tricky, but you might not want to do that anyway.
There are other products with more and better features like Infusionsoft and Office Autopilot, but I would suggest you get your head around Mailchimp first before opening your wallet so that you know what you want before you think about paying.
Good luck with it
Mark Neild
mark@coherence-solutions.com
+44 1189485996
[cid:86420D7E-DF03-4A2B-A55C-120E531C0A29@otago.ac.nz]
www.coherence-solutions.com