I have created a banner in illustrator for adding into an email. (I have actually pasted it into a table in word so that i can add text and photo before i copy it to the email). The banner is a rectangular topbanner and i have started by creating a new document (for web) and then tried various pixels. I have followed by saving the banner for web and devices as a jpeg and as a png (even export and saved for screen and 72 dpi).
No matter which way i do it my banner becomes very blurry. What do i do wrong?