Different email clients/browsers will render your html email differently and when they work in conjunction with one another (forward from PC Outlook 2010 to Mac Outlook 2013 for example) things get screwy. You could try to "forward" the email by sending the Marketo email to yourself and attaching it to an email in your email client. Another option is to send the email to yourself with the "view email in browser" option, take the URL, and hyperlink/incorporate the link into your email.