Adding an undersigned or signature block to your emails in Outlook makes your messages look professional and saves time. Whether you mean a simple typed name that follows Sincerely, a full contact block with job title and phone number, or a scanned handwritten signature image, Outlook provides several ways to add and manage signatures. This topic walks you through step-by-step instructions for Outlook desktop, Outlook on the web, and mobile apps. It also covers how to create multiple signatures, insert digital signatures for legal or security purposes, and format the undersigned so it looks clean and consistent across devices.
What Undersigned Usually Means in Email
In email terms, the undersigned refers to the person who signs off at the end of a message. That can be as simple as your typed name after a closing line like Best regards, or it can be a more detailed signature block that includes your title, organization, phone number, and even a logo or scanned signature. Knowing which type you need helps you choose the best method in Outlook.
Types of Signatures
- Simple text signature (name and title)
- Contact block (name, role, company, phone, website)
- HTML signature (styled block with links and icons)
- Image signature (scanned handwritten signature)
- Digital signature (S/MIME or certificate-based for security)
How to Add an Undersigned (Signature) in Outlook Desktop
The desktop version of Outlook (Microsoft 365, Outlook 2019/2016) gives you full control over signatures. Follow these steps to create, format, and automatically insert a signature into new messages and replies.
Step-by-step Create a Signature
- Open Outlook and go to the File menu, then choose Options.
- In the Outlook Options window select Mail from the left-hand menu.
- Click the Signatures…. button found in the Compose messages section.
- In the Email Signatures tab click New and type a name for the signature (for example Work Undersigned).
- Enter the text for your undersigned in the Edit signature box. Use the formatting toolbar to change fonts, add links, or insert an image (such as a scanned signature) via the image icon.
- Choose default signature settings pick the email account (if you have multiple) and select which signature to use for New messages and Replies/forwards.
- Click OK to save and close all dialog boxes.
Tips for a Professional Undersigned
- Keep it concise name, title, company, phone number, and one link (company website or calendar) are usually enough.
- Use a simple font like Calibri or Arial to ensure consistent display across devices.
- If you add an image, resize it before uploading so it doesn’t overwhelm the email.
- For legal or formal contexts, include your credentials and disclaimers if needed.
How to Add an Undersigned in Outlook on the Web (Outlook.com / OWA)
Outlook on the web gives a quick way to manage signatures when you’re away from your desktop. The steps are slightly different but just as straightforward.
Step-by-step Create a Web Signature
- Sign in to Outlook.com or your organization’s Outlook on the web.
- Click the gear icon (Settings) in the top-right corner and select View all Outlook settings at the bottom.
- Choose Mail, then Compose and reply.
- Compose your undersigned in the Email signature box. Use the formatting options to style text or insert an image.
- Select whether to automatically include the signature on New messages and on messages you forward or reply to.
- Click Save to apply changes.
How to Add an Undersigned in Outlook Mobile (iOS and Android)
Outlook’s mobile apps let you add a simple undersigned, though the formatting options are limited compared with desktop and web versions. Still, you can set a default text signature that will appear in messages sent from your phone.
Step-by-step Mobile Signature
- Open the Outlook app on your phone and tap your profile icon or the gear icon for Settings.
- Scroll to find Signature or tap the account you want to configure and then Signature.
- Enter your undersigned text. Keep it short because mobile signatures are best when concise.
- Save your changes.
Using a Scanned Handwritten Signature or Logo
If you want a personal touch, you can scan a handwritten signature and insert it as an image into your Outlook signature. Make sure the image has a transparent background or is cropped closely to avoid large white margins.
How to Insert an Image in Desktop Outlook
- Open Signatures in Outlook Options.
- In Edit signature click the image icon and select your scanned signature file (PNG recommended).
- Resize the image if needed and add text lines beneath such as your printed name and contact details.
- Save changes.
Digital Signatures for Security and Legal Use
For documents or emails that require secure, verifiable authenticity, use S/MIME or certificate-based digital signatures rather than just an image. Digital signatures provide encryption and prove the message came from you.
How to Use S/MIME in Outlook
- Obtain a digital certificate from a trusted certificate authority and install it in Windows or your device.
- In Outlook desktop go to File >Options >Trust Center >Trust Center Settings >Email Security.
- Under Encrypted email, choose Settings, select your certificate, and enable S/MIME for signing or encryption.
- When composing an email you can now choose to Sign or Encrypt the message from the Options tab.
Managing Multiple Signatures and Quick Insert
Outlook allows you to create several signatures and pick the right one while composing an email. This is useful for switching between a short undersigned and a full contact block, or for using different signatures for personal and business accounts.
Quick Insert in Desktop Outlook
- While composing a message, go to the Message tab and click Signature.
- Select the signature you want to insert from the dropdown menu.
- You can also edit signatures from this dropdown without leaving the compose window.
Best Practices and Troubleshooting
Keep a few best practices in mind test how your undersigned looks by sending messages to yourself and to recipients using other email clients, avoid large images, and keep mobile signatures concise. If a signature won’t appear, verify which account is active and check automatic insertion settings. Clearing Outlook’s cache or re-adding the account sometimes fixes stubborn issues.
Adding an undersigned in Outlook is a small task that boosts your professionalism and saves time. Whether you configure it in the desktop app, on the web, or in the mobile client, Outlook supports text, HTML, and image-based signatures. For formal or secure communication, consider digital signatures via S/MIME. By following the steps in this guide, you can create clear, consistent signatures that display properly across devices and help recipients know who you are and how to contact you.