At a high level, it is expected for emails to look different, even within the same platform such as Outlook 2013 vs Outlook 2010. With that said, you can code against some of these anomalies by adding extra code in CSS to account for the differences. You should consult with an HTML/CSS designer to make these changes.
In all likelihood, the issue is related to how Outlook(or any other email client) is rendering the email and reviewing the Outlook settings as well as email and template code should resolve any issues customers are experiencing as when we send test emails to both outlook and gmail both are generally rendered differently (gmail seems a bit fine though).
FAQs
Where should I start trying to determine whether this is a Marketo or Outlook issue?
In most cases if the email is loading within another email client without issue then Outlook would be the best location to review.
Is there a way for me to see if it is a template problem?
Yes, does the issue occur when an email is created and sent with another template?
What are the steps to troubleshoot?
In general, to provide the most accurate troubleshooting steps, a bit more information will be helpful. I have provided a few general tips below which may be helpful. As a rule of thumb, Outlook sometimes requires custom coding to appear as it does in other email clients since they use their own word engine to render the html.
If the images when they are downloaded are not displaying as expected, we would typically recommend reviewing any code in the email since Outlook uses its word engine to render html and additional code may be needed for Outlook specifically as a result. A developer may be required to implement any custom code required to display the emails as expected.
You may consider reaching out to the Community to understand what other users have done to overcome similar obstacles. I have provided a few links below which may be relevant.
Is there any reference Documentation ?
https://nation.marketo.com/docs/DOC-4765-why-does-my-email-looks-different-on-various-version-of-the...
HTML Email Display in Outlook
Marketo emails don't render properly in MS Outlook app for iOS
Re: Help - My Emails Look Terrible in Outlook 2016
Here are a few resources that may help with Outlook rendering issues:
It’s Not You, It’s Outlook – The Complete Guide for Email Marketers
http://www.verticalresponse.com/blog/its-not-you-its-outlook-the-complete-guide-for-email-marketers/
Gallery of Common Outlook Rendering Issues
Gallery of Common Outlook Rendering Issues
MICROSOFT OUTLOOK CONDITIONAL STATEMENTS
http://labs.actionrocket.co/microsoft-outlook-conditional-statements
Outlook 2007/2010/2013/2016 and Word HTML
Outlook 2013 / 2016 / 2019 / 365 and Word HTML - HowTo-Outlook
12 Techniques for Excellent Emails in Outlook.com
How to Create Excellent Emails for Outlook.com
A Guide to Rendering Differences in Microsoft Outlook Clients
Outlook Email Rendering Issues and How to Solve Them - Litmus
Surface Pro 3 and Outlook Email Rendering
Redirecting