How to add a signature that appears on every email you send

Open Outlook 365 in your web browser or desktop app. Go to Settings (the gear icon in the top right), then select View all Outlook settings. In the left sidebar, click Mail, then Compose and reply. Scroll down to the Signature section. Type or paste your signature text into the box, then check the box that says Automatically include my signature on messages I send. Click Save at the bottom of the page.

Your signature will now appear at the bottom of every new email you write. It will not appear on emails you forward or reply to unless you also check the box for Include my signature before quoted text in replies and forwards. This second option is useful if you want your name and contact details visible even when you are continuing a conversation.

Key Takeaways

  • Your signature appears automatically on new emails once you enable it in Outlook Settings under Mail and Compose and reply.
  • You can choose whether your signature shows on replies and forwards separately from new messages.
  • Signatures can include text, but Outlook 365 web does not support images or formatted fonts in the same way the desktop app does.
  • If you use multiple email accounts in Outlook, you can set a different signature for each account.

Where to find the signature settings in the desktop app

If you use Outlook on your computer (Windows or Mac), the path is slightly different. Open Outlook and go to File in the top menu. Click Options (Windows) or Preferences (Mac). Select Mail from the left sidebar, then look for Signatures. Click the Signatures button to open the signature editor.

The desktop version gives you more control. You can create multiple signatures and choose which one to use for new messages versus replies. You can also add formatting, fonts, colors, and images. Once you have created your signature, select it from the dropdown menu next to New messages and Replies and forwards, then click OK.

What to include in your signature and what to avoid

A professional email signature typically includes your name, job title, company name, phone number, and email address. Keep it to three or four lines. Avoid including sensitive information like your home address, Social Security number, or financial account details — your email signature is visible to everyone who receives your message, and it may be forwarded or stored in ways you cannot control.

If you are using Outlook for work, check your company's email policy first. Many organizations have rules about what signatures must include (like a legal disclaimer or company logo) or what they must not include (like personal social media links). If your company uses a centralized signature system, your IT department may push signatures to your account automatically, and you may not be able to change them.

Why your signature matters for privacy

Every signature you send is a data point about you that travels with your email. If you include your phone number, anyone who receives your email — or anyone who intercepts it — has that number. If you include your job title and company, you are telling recipients (and anyone reading your email later) exactly who you are and where you work.

This is particularly relevant if you receive marketing emails or sign up for services using your work email address. Your signature may be stored in the recipient's email system, in their backup files, or in forwarded copies of your message. Years later, that signature could be used to contact you or to verify your identity in ways you did not expect. If privacy is a concern, keep your signature minimal — name and email address are usually enough.

How to change or remove your signature later

To edit your signature, go back to the same settings page where you created it. In Outlook web, that is Settings > Mail > Compose and reply > Signature. Make your changes and click Save. In the desktop app, go to File > Options (or Preferences) > Mail > Signatures.

To remove your signature entirely, delete all the text in the signature box and uncheck the Automatically include my signature on messages I send box. Your emails will no longer include a signature. If you have multiple signatures set up, you can delete individual ones by selecting them and clicking Delete in the signature editor.

Setting different signatures for different email accounts

If you have more than one email account in Outlook 365, you can assign a different signature to each one. In the web version, the signature you create applies to whichever account you are currently signed into. If you switch accounts, go back to Settings and create a new signature for that account.

In the desktop app, the process is clearer. When you create a signature, you will see a dropdown menu that says E-mail account. Select the account you want the signature to explore to, then create the signature. Repeat for each account. This way, your work email can have a formal signature with your title and company, while your personal email can have something simpler.

Troubleshooting: why your signature might not be appearing

If you have turned on automatic signatures but they are not showing up, first check that you actually saved your changes. In the web version, look for a green checkmark or confirmation message at the top of the page. If you do not see one, click Save again.

If the signature still does not appear, try signing out of Outlook completely and signing back in. Sometimes the browser cache prevents the new setting from taking effect. In the desktop app, close Outlook entirely and reopen it. If you are using Outlook on your phone or tablet, note that mobile apps often do not support automatic signatures — you may have to add your signature manually to each message, or use the desktop or web version instead.

Frequently Asked Questions

Can I use HTML code or images in my Outlook signature?

The web version of Outlook 365 has limited formatting options — you can use bold, italic, and color, but not custom HTML or images. The desktop app supports images and more complex formatting. If you need a logo or advanced design, use the desktop version and upload an image file from your computer.

Will my signature appear on emails I send from my phone?

Not automatically. Outlook mobile apps do not sync signatures the way the web and desktop versions do. You can add a signature manually in the mobile app settings, but it will be a separate signature just for your phone. Most people use a straightforward text signature on mobile and a more detailed one on desktop.

What happens to my signature if I change my password?

Your signature is stored separately from your password, so changing your password will not affect it. Your signature will continue to appear on outgoing emails. If you lose access to your account entirely, you will need to recover your account before you can edit your signature again.

Can I schedule when my signature appears on emails?

No. Outlook does not have a built-in feature to schedule signatures to appear only at certain times or on certain days. Your signature will appear on every email you send once it is enabled. If you need different signatures for different purposes, create multiple signatures and manually select which one to use for each message.

Is my signature encrypted when I send an email?

Your signature travels with your email in plain text unless you use end-to-end encryption on the entire message. If you send a regular unencrypted email, anyone who intercepts it can read your signature. If you use Outlook's encryption feature (available in some enterprise accounts), the signature is encrypted along with the rest of the message.