Mobile Responsive Email Signature

A mobile responsive email signature is one whose layout adapts to the viewport width of the device viewing the email. On wide screens (desktop email clients), the signature renders in its full multi-column layout. On narrow screens (mobile email clients with viewport widths under 600 pixels), the layout collapses to a single column, the logo and contact details stack vertically, and text sizes scale up to remain readable. Responsive behavior in email signatures uses CSS media queries inside the signature HTML, which most modern email clients support but Outlook desktop does not. Fallback approaches include using max-width on table cells and pixel widths that work acceptably both narrow and wide. The objective is that the signature looks intentional and readable whether the recipient opens the email on an iPhone or a 27-inch monitor.