Outlook Signature Not Showing? 9 Common Fixes (2026)

Quick fix: 90% of the time an Outlook signature “not showing” means no default was set. Open your signature settings, and for the correct account set a signature for both New messages and Replies/forwards. In new Outlook and Outlook on the web that is Settings → Accounts → Signatures; in classic Outlook for Windows it is File → Options → Mail → Signatures.

If that is not it, the cause is almost always one of a handful of things: the wrong account, a mismatch between new and classic Outlook, a mobile app with its own settings, plain-text formatting, or a blocked image. Work through the list below in order.

1. No default signature is selected

This is the most common cause by far. Creating a signature does not make Outlook use it, you also have to assign it as the default.

• New Outlook / web: Settings → Accounts → Signatures. Under “Select default signatures”, set your signature for New messages and for Replies/forwards.
• Classic Outlook (Windows): File → Options → Mail → Signatures. On the right, set the defaults for New messages and Replies/forwards.

If you only set one, your signature will appear on new emails but not replies (or the reverse). Set both.

2. The signature is assigned to the wrong account

Signatures and their defaults are set per account. If you have more than one mailbox in Outlook, you may have assigned the signature to the wrong one.

In the Signatures window, use the Email account dropdown (classic) or confirm the account shown (new/web) and set the default for the account you actually send from.

3. You are mixing new Outlook and classic Outlook

New Outlook for Windows and classic Outlook are effectively different apps, and a signature created in one does not automatically appear in the other. New Outlook stores signatures in the cloud (roaming signatures); classic Outlook historically stored them on the local PC.

If you recently switched, recreate or re-confirm your signature in the version you are actually using. If you toggle between the two, set the signature in both.

4. Your mobile Outlook has its own signature

The Outlook mobile app does not inherit your desktop signature by default. It ships with “Get Outlook for iOS/Android” and you have to replace it.

On mobile: open the app → tap your profile → Settings → Signature, and enter your signature there. Note that Outlook mobile signatures are plain text, so a full branded HTML signature will not carry over from desktop.

5. The message is in plain text format

A signature with formatting, links, or images only renders in HTML messages. If your message (or your default compose format) is set to plain text, the HTML signature is stripped.

In classic Outlook: File → Options → Mail → Compose messages in this format → set to HTML. In the compose window, check the Format Text tab and confirm HTML is selected.

6. Images in the signature are not loading

If the text shows but your logo does not, it is usually one of these:

• The recipient blocked images. Many mail clients hide external images by default. This is on the recipient’s side.
• The image was linked, not embedded, and the URL is unreachable or blocked.
• The image was removed when the signature was saved. Rebuild the signature and re-insert the image.

Server-side signatures (see #8) are especially prone to logos arriving as attachments or broken images, because the picture has to be hosted externally.

7. Roaming signatures are disabled or out of sync

New Outlook and Outlook on the web use roaming signatures stored in your mailbox so they follow you across devices. If your organization has roaming signatures turned off, or the mailbox has not synced, a signature you set in one place may not appear in another.

Give it a few minutes to sync, sign out and back in, or ask your admin whether roaming signatures are enabled for your tenant.

8. Your company uses a server-side signature (so you will not see it while composing)

If your IT team applies signatures with an Exchange mail flow rule (a disclaimer), the signature is added after the message leaves Outlook. That means you will never see it in the compose window, and it lands at the very bottom of the thread. It is working, you just cannot see it before sending. Send yourself a test email to confirm.

This is one of the real downsides of the server-side approach. For the full picture, see our guide to deploying Microsoft 365 email signatures to all users.

9. A signature add-in is disabled or not deployed

If your team uses an add-in-based signature manager and signatures suddenly stop appearing, the add-in may have been disabled or not deployed to that user. In Outlook, check Get Add-ins / Manage Add-ins and confirm it is enabled, or ask your admin to confirm the add-in is deployed to your account from the Microsoft 365 admin center.

Still not working? Rebuild it from scratch

If you have been through the list and the signature still will not appear, delete it and create a fresh one. Corrupted signature data (particularly in classic Outlook, stored under %appdata%\Microsoft\Signatures) can cause odd behavior that a clean rebuild resolves. Our step-by-step Outlook signature guide walks through it for every version.

If this keeps happening across your team

One person fixing their own signature is quick. A whole team where signatures keep going missing, showing up inconsistently, or breaking on replies is a management problem, not a settings problem. When each person sets their own, something is always wrong somewhere.

The durable fix is to stop relying on individual settings and deploy signatures centrally. With Firma, an admin designs one on-brand signature and deploys the Firma add-in from the Microsoft 365 admin center, so the right signature applies automatically in Outlook on desktop, web, and mobile, on new emails and replies, with images that render. Update it once and it rolls out to everyone. See Microsoft 365 email signatures and centralized email signature management for how it works.

Frequently asked questions

Why is my Outlook signature not showing on replies? Outlook sets defaults separately for new messages and for replies and forwards. Open your Signatures settings and make sure a signature is selected in the Replies/forwards dropdown, not just New messages.

Why did my signature disappear after switching to new Outlook? New Outlook and classic Outlook store signatures separately, so a signature from classic does not automatically carry over. Recreate it in new Outlook, or confirm roaming signatures have synced.

Why does my signature show for me but not for the recipient? Usually the message was sent as plain text (which strips the signature) or the recipient’s client blocked the signature images. Confirm you are composing in HTML, and test with an embedded or reliably hosted logo.

Why is my logo showing as a red X or an attachment? The image is linked to a URL that is blocked or unreachable, or a server-side signature is hosting it externally. Signatures applied directly in Outlook render images far more reliably than server-side disclaimers.

How do I stop signatures from going missing across my whole team? Do not rely on each person’s Outlook settings. Deploy a signature manager that applies the signature for everyone automatically. See how to deploy Microsoft 365 email signatures to all users.