To update your signature in Microsoft Outlook, follow these general steps:

1. Open Outlook.
2. Go to "File" > "Options" > "Mail".
3. Click on the "Signatures..." button.
4. Select the signature you want to update from the list.
5. Edit your signature content in the "Edit signature" box.
6. Click "Save" and then "OK" to apply changes.

Alternatively, you can edit your signature from a new email message:

• Start a new email.
• Click the "Signature" dropdown in the message window.
• Choose "Signatures..."
• Select or create a signature and make changes.
• Save the updated signature.

You can also set your signature as default for new messages and replies/forwards in the signature settings. This process works similarly in both the desktop and web versions of Outlook, with slight navigation differences. For mobile Outlook apps, update signatures from the settings menu under Signature. These instructions apply broadly across Outlook for Windows, Mac, and Outlook Online as of 2025.