Outlook breaks button text because of its Word rendering engine. Instead of white-space:nowrap;, try: Add display:inline-block to the <a> tag. Set a min-width on the <td> (e.g. min-width:135px;). Use mso-line-height-rule:exactly; to prevent stacking issues. This keeps Gmail responsive while stopping Outlook from wrapping your two-word CTA button. Testing on real devices and clients is always recommended because Outlook and Gmail render emails very differently. We’ve solved similar quirks when building responsive email templates at Apponward.