Productivity30 May 2026· 4 min read· Nagy Rudolf

Email Signatures That Look Professional in Every Client

Half of all signatures break in Outlook. The fix is knowing which twenty-year-old rendering rules still apply.

Your signature is appended to every message you send, and it is rendered by clients whose HTML support ranges from modern to 1999. Designing for the worst one is the whole job.

What belongs in it

Name, role, company, one phone number, one link. Optionally a legal line if your jurisdiction requires company registration details on business correspondence — Germany, Hungary and the UK all have variants of this rule.

What does not

Inspirational quotes, an environmental plea about printing, five social icons, a photo of yourself, and a confidentiality disclaimer longer than the message. Each one adds weight to every email in a thread; after a ten-message exchange the disclaimer has been sent ten times.

Rendering rules that still matter

  • Tables, not flexbox or grid. Outlook's rendering engine is Word's.
  • Inline styles only. <style> blocks are stripped by several clients.
  • Web-safe fonts. Arial, Helvetica, Georgia, Verdana. Custom fonts silently fall back.
  • No background images. They are blocked or ignored widely.
  • Text links, not image links. Images are blocked by default in many clients, and an image-only signature then shows nothing at all.
  • Under 600 px wide, so it does not force horizontal scrolling on mobile.

Logos

If you must include one, keep it under 20 KB, host it on a stable HTTPS URL, set explicit width and height so the layout does not jump, and always provide alt text — for many recipients the alt text is what they will see.

Building one

The email signature generator produces clean table-based HTML from a few fields and lets you copy it straight into your mail client's signature settings. Send yourself a test to Gmail web, the Outlook desktop app and a phone before rolling it out to a team.

For teams

Consistency beats individuality. One template, one set of fields, one link. Store it in a shared doc so new joiners do not invent their own.

FAQ

Why does my signature look broken in Outlook? Almost always CSS layout instead of tables.

Should I include a pronoun line? It is common and harmless; follow your organisation's convention.

Do disclaimers have legal force? Very limited. Include only what regulation requires.

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