xghost

I think that "composer" is the name of the component you get if you click "write" in Thunderbird to "compose" new mail. You could import all the addresses you wish to mail to into Thunderbird's address book. Images that you insert are included in the document so you would not need to upload them to a server. One can make great looking mail for recipients who receive mail in html using this, ...but... now I wonder if that would work for you since, if you are to send a newsletter to lots and lots of email addresses, and many people only view their mail in plain text, you will need something that still looks good for those readers as well? You might try making a test sample and sending it to yourself in both html and plain text just to see.

Hi wingzero2309 Mozilla Thunderbird's composer might work for you. It will let you make tables, (which you could use to format the newsletter in columns if you want), insert images, links, format the page background or table backgrond with custom colors or images, etc... Nice mail program. You can download it at: http://www.mozilla.org/products/thunderbird/