Hello Esther,
Do you have the Deliverability Power Pack/IBM deliverability testing tool? If so, you can use this service to check how your messages look on a variety of mobile clients. To check, click on any email in design studio or marketing activities. If there's a button for "deliverability tools" at the top near the "send test" button, you have this service. If not, contact your sales rep to discuss adding this option to your account.
For a bit more information, search our Help Articles on IBM.