How to setup an auto newsletter emailing list?

Hi there; new here and I was just wondering if anyone could tell how to make an automatic mailing list in mac mail? I don't know if that is the name- basically I wanted something that I can write an email say one day from Monday to Saturday and have it put in a folder and at a set time probs on Sunday night/Monday morning it is sent out- basically a news letter for a mailing group - does that make any sense? sorry I can't be more precise...
Thanks in advance for any help.

I believe what you will be doing is create the newsletter and a file/document of e-mails and use either a shell script or AppleScript to sent out the e-mail each day.