If you are using HTML to design your email campaigns, you've probably noticed that Outlook has a nasty habit of ruining them. Tables, padding, and background images are all fair game for Outlook, and there are many other elements that the email client will happily chew up for you too.
Outlook uses Microsoft Word to render emails. MS Word is not friendly when it comes to HTML. If you're sending emails with HTML in them, you're probably going to run into some problems because of this.
There are some email elements that will break in Outlook, if a large portion of your contacts use Outlook, it is a good idea to avoid these entirely:
When you need to use padding or width on your elements, try using the hspace or vspace attributes instead.
Outlook will also cause problems for you if you use the following elements in your HTML emails:
Everlytic has a built-in compatibility tester which you can use to preview your emails and see how they might render in Outlook. This tool analyses your email to evaluate how it may display in common email clients. A client with a red cross next to its name contains incompatibilities. If you click on the email client name, you will see a list of any unsupported styles.
Another good idea is to create a test list with email addresses in Outlook where you can receive test emails. Before sending to your contacts, send test emails to yourself. This will allow you to see what the emails will look like in a live Outlook environment.