A signature block is text that appears automatically at the bottom of every email you send

A signature block is a block of text — usually your name, title, phone number, and sometimes a company logo or disclaimer — that Outlook adds to the end of every email you send. Instead of typing your contact details into each message, you set it up once and Outlook handles it from then on.

This matters for security because a signature block can include a legal notice that reminds recipients not to share sensitive information, or it can make clear which email address is actually yours (so someone cannot impersonate you as easily). It also matters because a signature block you did not create is a sign that someone else has access to your account — if emails go out with a signature you never set up, that is a red flag to investigate.

Key Takeaways

  • You can create a signature block in Outlook by going to File > Options > Mail > Signatures and typing in your text.
  • Outlook lets you set different signatures for new emails and for replies, so your outgoing mail can look different from your responses.
  • A signature block appears automatically on every email unless you delete it before sending, which takes one click.
  • If you see a signature block you did not create, change your Outlook password when ready and check your account recovery options.

Where to find the signature settings in Outlook

The path depends on whether you use Outlook on your computer or Outlook on the web. On your desktop version, go to File in the top left, then Options, then Mail in the left sidebar, then Signatures. You will see a button that says New — click it to create your first signature.

If you use Outlook on the web (the version you access through a browser), the path is different. Click the gear icon in the top right, then View all Outlook settings, then Mail in the left sidebar, then Compose and reply. Scroll down until you see Email signature and type your text directly into the box.

What to include in your signature block

A basic signature includes your full name, job title, company name, phone number, and email address. You can add a physical mailing address if you want, though that is less common for security reasons — the more contact details you publish in every email, the easier it is for someone to find you offline.

Many organizations add a legal disclaimer, such as "This email and any attachments are confidential and intended only for the named recipient." This does not actually protect you legally, but it reminds people not to forward sensitive information. Some companies add a logo or a link to their website. Keep it short — most people scan signatures quickly, and a wall of text gets ignored.

Setting up different signatures for new emails and replies

Outlook lets you use one signature for brand-new emails and a different one for replies and forwards. This is useful if you want your outgoing mail to look formal but your replies to be shorter. In the desktop version, after you create your first signature, you will see two dropdown menus: one for New messages and one for Replies and forwards. You can assign the same signature to both, or create a second signature and assign it to replies only.

To create a second signature, click New again and give it a different name — for example, "Formal" and "Reply". Type the text for each one, then use the dropdowns to choose which signature goes where. If you leave either dropdown blank, Outlook will not add a signature to that type of email.

How to remove or edit your signature before sending

Even though your signature appears automatically, you can delete it from any single email before you send. Open the email, highlight the signature text at the bottom, and press Delete. The signature will not appear on that one email, but it will come back on the next email you write.

To edit your signature permanently, go back to File > Options > Mail > Signatures (or the web version equivalent), find the signature you want to change, edit the text, and click Save. The change takes effect on all new emails from that point forward — it does not change emails you already sent.

What to do if you see a signature you did not create

If an email goes out with a signature block you never set up, someone else may have access to your account. This is a security problem that needs when ready attention. Change your Outlook password right away — use a password you have never used before, make it at least 16 characters long, and include uppercase letters, numbers, and symbols.

After you change your password, check your account recovery options. Go to your Microsoft account page (account.microsoft.com), click Security, then Advanced security options, and review which phone numbers and email addresses are listed. If you see a recovery email or phone number you do not recognize, remove it. Also check Recent activity to see where your account has been signed in from — if you see cities or devices you do not recognize, sign out of all sessions and review your connected apps.

Signature blocks on mobile Outlook

The Outlook app on your phone or tablet does not let you create a signature block the same way the desktop version does. Instead, you have to set it up on your computer first, and then the signature will appear automatically on emails you send from the mobile app.

If you use multiple devices and want different signatures on each one, you will have to change your signature settings on each device separately. The mobile app does not sync signature settings across devices the way it syncs your inbox.

Frequently Asked Questions

Can I use HTML or images in my signature block?

Yes, but only in the desktop version of Outlook. In the Signatures window, you can click the formatting buttons to make text bold or italic, and you can insert an image by clicking Insert > Image. The web version only accepts plain text, so any formatting will be stripped out.

Why does my signature appear twice on some emails?

This usually happens when you reply to an email that already has your signature at the bottom. Outlook adds your signature to the reply, so now there are two. You can delete the old one manually, or you can turn off the setting that includes the original message in replies — though most people want to see what they are replying to.

Can I have different signatures for different email accounts?

Yes. If you have multiple email accounts set up in Outlook, you can create a separate signature for each one. In the Signatures window, you will see a dropdown that says Email account — select the account you want, then create or edit a signature for just that account.

What if I want no signature at all?

Leave both the New messages and Replies and forwards dropdowns blank, or select None from each one. Outlook will not add a signature to any email unless you manually type one in.