One email signature for Gmail and Outlook: how to

One signature can work in both Gmail and Outlook if it follows email HTML rules: a table layout, inline styles, hosted PNG or JPG images with set sizes, and web-safe fonts. What breaks is anything designed like a web page or a document, such as CSS layout, SVG logos, background images or custom fonts. Build to the strictest client, classic Outlook for Windows, and Gmail will be fine.

Small business owners ask some version of "how do I get a signature that plays nice with Outlook and Gmail?" all the time, usually after paying a designer for a beautiful one that falls apart.

Why the two differ

• Gmail strips some CSS, rewrites image addresses through its own proxy and rejects signatures over 10,000 characters of HTML.
• Classic Outlook for Windows renders email with Microsoft Word's engine. It ignores rounded corners, many margins and most modern CSS.
• Outlook on the web and the new Outlook are more modern, but still email clients, not browsers.

The rules

1. Tables for layout. No CSS grid or flexbox.
2. Inline styles. Put styles on each element. Do not rely on a style block.
3. Hosted images. PNG or JPG on a public HTTPS address. No SVG, no base64.
4. Width and height on every image. Outlook depends on them.
5. Web-safe fonts. Arial, Helvetica, Georgia, Verdana or Tahoma. A custom web font will fall back anyway.
6. No text inside images. Your name and phone stay as real text.
7. Under 10,000 characters. For Gmail. See size limits.

Expected differences

Some differences are normal even with a perfect signature:

• Classic Outlook shows round photos as squares.
• Line spacing may be slightly larger in classic Outlook. See extra space between lines.
• Gmail may show images slightly later because it loads them through its proxy.

Installing it

Copy the signature as formatted content, not as code, and paste it into each client:

• Add a signature in Gmail
• Outlook install guide
• Outlook for Mac

Where Sendoff fits

Sendoff builds every template to these rules, and preview and export come from the same renderer. Make one in the free email signature generator, then use the copy button for Gmail or Outlook. There are dedicated pages for the Gmail signature generator and Outlook signature generator.

FAQ

Can I write the HTML myself? Yes, if you follow the rules above. Test in classic Outlook for Windows first.

Why does my Canva or Word design not work? They export images or document markup, not email HTML. Rebuild the layout as a table.