Go ahead and try HTML. With Aweber it’s easy.

In sending messages I use “dual format”–plain text and HTML–for newsletters and most often plain text for promotional mailers.

Dual format is when you send both an html and plain text newsletter in the same “package.” Most people will automatically see the html, but those who choose to view plain text will see the plain text.

The newsletters tend to build my credibility.

For promotional emails I most often want them to be similar to “regular” emails my subscribers would get from Aunt Martha. So I most often use plain text.

Deliverability for html (or dual format) is virtually identical to plain text. Your recipients seeing the images can be a problem, so you need to create a link to view the message online as well as make the message meaningful and appealing even without images (like using blocks of color rather than images to create backgrounds and borders.)

This comment makes it sound complicated, but it is really pretty simple once you have a template. Aweber gives you many template options or you can create your own cheaply.