How to Make Your Email Signature Mobile-Friendly
Well over half of email opens happen on phones — where a desktop-designed signature becomes a tiny, untappable mess. Mobile-friendly is mostly five decisions.
Step by step
Design at 500px, allow 320
Keep the signature's natural width ~500px with max-width:100% so it shrinks gracefully to phone width instead of forcing horizontal scroll.
Make columns stack
Side-by-side layouts (photo | details) need a media query that stacks them vertically under ~480px. Email-safe stacking uses table-based markup with responsive overrides — fiddly by hand, built into good templates.
Size every image explicitly
Explicit width/height attributes stop phones from inflating the logo to full width (the classic 'logo is massive on my phone' complaint).
Or skip the manual setup
Autograph designs the signature on your Mac and installs it into Apple Mail in one click — images hosted at permanent URLs, assigned to the right account, and re-applied automatically when a macOS update or iCloud sync wipes it.
Download freeUnlock Pro — one-time, no subscriptionMake contacts tap targets
Phone as tel:, email as mailto:, address as a maps link. On mobile these aren't conveniences — they're the whole point. Keep tappable elements ≥40px apart so thumbs don't misfire.
Respect font minimums
Below ~13px, iOS may auto-inflate text unpredictably. Explicit 13–15px body sizes render consistently.
Test on an actual phone
Send yourself a test and read it on the phone — then tap every link. Simulators lie about thumbs.
Responsive by default
Every Autograph template stacks correctly on phones — you can preview the mobile rendering in the app before you install.
Download Autograph free See the templatesCommon questions
Why does my signature force sideways scrolling on phones?
A fixed width over ~600px (or an unsized wide image). Add max-width:100% and explicit image dimensions.
Do mobile clients support the same HTML as desktop?
Mostly — iOS Mail and Gmail apps render well. The differences that bite: media-query support varies, so table-based responsive markup beats flexbox tricks.
Is a separate mobile signature worth it?
No — one responsive signature is less to maintain and can't get out of sync. That's how Autograph templates are built (they even preview in a phone frame in the gallery).
The Apple Mail Signature Fix Kit
A free checklist: why Apple Mail signatures vanish after macOS updates, the iCloud sync gotcha that wipes them, and how to make your images render in Gmail and Outlook. Straight to your inbox.