How to Add an Email Signature in Outlook

Here's the thing about email signatures: they're one of those small details that make a surprisingly big difference. Every email you send is a tiny business card — and right now, yours might be blank.

A professional signature builds trust before anyone has even replied. It tells the recipient who you are, how to reach you, and that you take your communication seriously. Setting one up in Outlook takes about 3 minutes, and this guide covers every version and platform so there's no guesswork.

Updated: March 2026·~3 min read·Works with: Outlook 2016, 2019, 2021, 365, OWA, Mobile

Quick Answer

Windows: File → Options → Mail → Signatures → New → paste content → assign default → OK
Mac: Outlook → Preferences → Signatures → + button
Web: Settings gear → View all settings → Mail → Compose and reply → paste → Save

Build Your Outlook Signature First

SignForge generates Outlook-compatible HTML (table layout, inline CSS). Create it free, then paste into Outlook.

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Works with Gmail, Outlook, Apple Mail & more

Add a Signature in Outlook on Windows

Applies to Outlook 2016, 2019, 2021, and Microsoft 365 (classic desktop app).

Open Signature Settings

Click File → Options → Mail → click the Signatures… button in the “Compose messages” section.

Create a New Signature

Click New. Enter a name for the signature (e.g. your name or “Work”). This is an internal label only — recipients don't see it.

Add Your Content

Click inside the editing box and type your signature, or paste from SignForge using Ctrl+V. The HTML formatting — bold text, colors, images, links — is preserved when pasting.

Assign a Default

Under Choose default signature: select your email account from the dropdown, then set your new signature for New messages. Optionally set it for Replies/forwards too (many people use a shorter signature here).

Save

Click OK. Open a new compose window — your signature should appear automatically.

Pro Tip

Create two signatures: a full one for new emails and a stripped-down one (just name and phone) for replies. This keeps threads clean while still making a great first impression.

Add a Signature in Outlook on Mac

Open Preferences

In the menu bar: Outlook → Preferences (or Cmd + ,).

Click Signatures

Click Signatures in the Preferences window.

Add a New Signature

Click the + button. Give it a name. Type or paste your signature in the content area.

Set as Default

Use the Choose Signature dropdown next to your email account to select your new signature. Close the window — saves automatically.

Add a Signature in Outlook Web (OWA)

Outlook Web (outlook.com or your company's OWA portal) stores signatures separately from the desktop app.

Open Settings

Click the gear icon (top right) → View all Outlook settings.

Navigate to Signature

Go to Mail → Compose and reply.

Paste Your Signature

Click in the signature editor box and paste your content. OWA preserves rich HTML including images and social icons.

Enable Auto-Insert and Save

Check “Automatically include my signature on new messages I compose”. Click Save.

Add a Signature in Outlook Mobile (iOS & Android)

Mobile signatures in the Outlook app are plain text only. For a rich HTML signature on mobile, set it up in Outlook Web — emails sent from the web version will include the full formatted signature.

Open App Settings

Tap your profile photo (top left) → tap the gear icon (bottom left).

Tap Signature

Find and tap Signature. Toggle Per Account Signature to set different signatures per account.

Type and Exit

Type your plain-text signature. Tap the back arrow — the app saves automatically.

Pro Tip

If you need a rich HTML signature on mobile Outlook, set it up in Outlook Web (OWA) instead. Emails composed in OWA carry the full formatted signature, even on your phone's browser.

Why Outlook Signatures Need Table-Based HTML

Outlook uses Microsoft Word's HTML rendering engine — not a browser. This means CSS flexbox, CSS grid, and float layouts don't work in Outlook signatures. All multi-column layouts must use HTML tables. All CSS must be inline (no <style> blocks).

SignForge generates signatures using table-based HTML with inline CSS, which renders correctly across all Outlook versions. If you're building your signature manually, test it in Outlook before rolling it out.

Related Guides

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Works with Gmail, Outlook, Apple Mail & more