How to Add an Email Signature in Outlook

Adding a signature in Outlook creates a named signature block that Outlook inserts automatically into new emails, replies, or both. Each email account in Outlook can have its own default signature. This guide covers all versions and platforms.

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.

Create My Signature →

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.

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.

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

Ready to Add a Professional Outlook Signature?

6 professional templates. Custom colors. Social links. No signup required — free forever.

Create My Signature →

Works with Gmail, Outlook, Apple Mail & more