Please test your emails on multiple email clients, to ensure your emails look good on all devices, on all apps, in all web mail clients etc. Learn how to format your emails for the most widespread readability and professional layout.
MS email clients are notorious for not implimenting the full set of HTML/CSS rules, so that your newsletters can look more awesome. You should thoroughly test your email templates in all diffent email clients to ensure it looks good in all.
If you use a simple format for your email, then you will have the best readability across all devices and applications.
Use simple headings, paragraphs and full width (or original width images)
Avoid using column layouts, avoid using left aligned or right aligned elements, as these do not display well in MS Outlook.
Old fashioned tables are great for laying out columns, but make sure your images "fit" in the boxes. Images should not be too big nor too small. While editing, the image may look correct in a web browser. However, when you send the email, the email client may decide to use the "actual size" of the image, which may cause your email to blow out unexpectantly. You can crop the pixel sizes of new images within our image wizard.
The preferred width of a email is 600 pixels. This will look quite narrow in our CMS editor, but when viewing on mobile devices, it will look about right. You might even consider having a smaller width if you are targeting a younger market who uses their mobile devices to read emails.
From a basis of 600px, you might have a half width image that is 300px, or a quarter width image that is 150px, etc.
Link buttons do not always display correctly in all email clients.