How to display Border Radius on Outlook

<div style="border: 2px solid grey; border-radius: 5px; padding: 20px;"><p><span style="font-family: 'museo-sans', sans-serif;"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">Hello</span></span></span></p><p>&nbsp;${mail_script:notification_logo}</p><table style="width: 100%;"><tbody><tr><td style="height: 40px;" colspan="5"><p><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">You Project(${URI_REF}) has been submitted and is being reviewed by&nbsp;<strong>${u_project_manager}</strong>.</span></span></p><p>&nbsp;</p></td></tr><tr><td style="background-color: #e6e7e8; color: #396b53;" colspan="5"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 500;"><strong>Title</strong></span></span></td></tr><tr><td style="color: black;" colspan="5"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">${short_description}</span></span></td></tr><tr><td style="background-color: #e6e7e8; color: #396b53;" colspan="3"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 500;"><strong>Submitted by</strong></span></span></td><td style="background-color: #e6e7e8; color: #396b53;" colspan="1"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 500;"><strong>Approver</strong></span></span></td><td style="background-color: #e6e7e8; color: #396b53;" colspan="1"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 500;"><strong>Department</strong></span></span></td></tr><tr><td style="color: black;" colspan="3"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">${submitter}</span></span></td><td style="color: black;" colspan="1"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">${u_project_manager}</span></span></td><td style="color: black;" colspan="1"><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 300;">${department}</span></span></td></tr></tbody></table><hr /><p>&nbsp;</p><p><span style="font-family: 'museo-sans', sans-serif;"><span style="font-weigth: 500;">Thank you,<br /></span><span style="font-family: 'Montserrat', sans-serif;">IT Service Desk</span></span></p><p>&nbsp;</p></div>