Avoid using images as your
sole content. Try to use the 80/20 rule: 80% text to 20% images. The main reason
for this is that images may be automatically blocked in email clients (such as
MS Outlook).
Break your email up into short blocks of text. Large blocks of text appear more daunting and may never be read.
Place important content to the top and left of your newsletter and avoid very
large headers or logos. When testing your newsletter, look at the newsletter in
the MS Outlook preview pane. Is enough of the content visible to inspire your
recipient to scroll further down the newsletter?
Fonts: Try to stick to fonts that are widely available.
Sans serif: Arial,
Verdana,
Trebuchet Serif:
Times New Roman,
Georgia
Text size: try to avoid text
that is either too small or too large. Large text in a newsletter may well
cause the email to be filtered out
as spam. And don't forget - NO SHOUTING!
September 2008 Top 10 Email Clients used by Businesses and Consumers
The biggest study of email client usage ever conducted, using a sample of almost three million email recipients!
This will help you decide which email clients to test on. From Litmus