Email signature not updating

Summary

This guide helps you troubleshoot and resolve: Email signature not updating. Follow the steps below to fix the issue.

Common Causes

Resolution steps

1. Verify Outlook signature settings

   • Open Outlook.
   • Select File from the top menu.
   • Choose Options, then select Mail from the left pane.
   • Click Signatures….
   • In the Choose default signature section, confirm the correct signature is selected for New messages and Replies/forwards.
   • If the signature is missing, select New, enter a name, paste the required HTML or text, and click OK.

2. Check the signature file location

   • Signature files should reside in %APPDATA%\Microsoft\Signatures.
   • Press Windows+R, type %APPDATA%\Microsoft\Signatures, and press Enter.
   • Confirm the files (.htm, .rtf, .txt) are present and not corrupted.

3. Clear Outlook cache

   • Close Outlook completely.
   • Press Windows+R, type %LOCALAPPDATA%\Microsoft\Outlook\RoamCache, and press Enter.
   • Delete the cache files in this folder.
   • Restart Outlook and re‑check the signature.

4. Confirm Exchange/Office 365 signature policy

   • Some organisations enforce a server‑side signature via Exchange Online. If a policy is applied, local changes in Outlook will be overwritten.
   • To verify, open Outlook Web App in your browser.
   • Select Settings (gear icon) → Mail → Compose and reply → Email signature.
   • If a policy signature is displayed and cannot be edited, contact your administrator to request an amendment.

5. Test in Outlook Web App (OWA)

   • Log in to Outlook Web App via your browser.
   • Compose a new message and verify the signature appears correctly.
   • If the signature works in Outlook Web App but not in Outlook, the issue is client‑side.

6. Ensure the signature format matches the message format

   • When composing a message, check that HTML is selected, not Plain text.
   • A plain‑text message will strip any HTML signature formatting.

7. Check for third‑party signature management tools

   • Applications such as Exclaimer or CodeTwo can override Outlook’s signature settings.
   • Open Outlook and select File → Options → Add‑Ins.
   • At the bottom, select COM Add‑Ins from the Manage dropdown and click Go….
   • Uncheck any signature management add‑ins and click OK.

8. Check internet connectivity and mailbox health

   • Ensure you have a stable internet connection; intermittent connectivity can prevent signature sync.
   • If you experience broader mail issues, see Email not sending or receiving.

Server‑side signature management

Microsoft 365 admin center

• Small businesses can manage organisation‑wide signatures through the Microsoft 365 admin center.
• Sign in to Microsoft 365 admin center with administrator credentials.
• Navigate to Settings → Org settings → Signatures.
• Review whether a default signature is applied to all mailboxes. If so, local Outlook changes will be overwritten by the server‑side policy.

Exchange Online PowerShell

• Administrators can use Exchange Online PowerShell to view or configure server‑side signatures.
• Connect to Exchange Online PowerShell using an administrator account.
• Run Get-OwaMailboxPolicy -Identity "Default" to review the current Outlook Web App policy settings.
• If a disclaimer or signature rule is configured, contact your IT administrator before making local changes.

Shared mailboxes and delegate access

• Signatures configured in your personal Outlook profile do not automatically apply when sending from a shared mailbox.
• If you have delegate access or Send As permissions for a shared mailbox, open the shared mailbox in a separate Outlook profile or use the From field in a new message.
• Set the signature separately within that shared mailbox profile if required.
• Server‑side signatures managed through Exchange Online may apply to shared mailboxes depending on the transport rule configuration.

Mobile email apps

iOS Mail

• Open Settings on your iPhone or iPad.
• Scroll to Mail and select Signature.
• Enter or edit your signature. Choose All Accounts or Per Account as needed.
• Changes apply only to the iOS Mail app and do not sync with Outlook desktop.

Android Outlook app

• Open the Outlook app.
• Tap your profile icon, then select Settings.
• Choose the email account, then tap Signature.
• Enter or update your signature and tap the checkmark to save.

Android Gmail app

• Open the Gmail app.
• Tap the menu icon, then scroll to Settings.
• Select the email account.
• Tap Mobile signature, enter your signature, and tap OK.

Cached credentials and modern authentication

• Cached credentials or outdated modern authentication tokens can prevent signature changes from syncing between Outlook and Microsoft 365.
• If you recently changed your password or your organisation updated authentication settings, sign out of Outlook and sign back in.
• In Outlook, select File → Account Settings → Account Settings, choose your email account, and select Repair to refresh credentials.
• Restart Outlook after signing back in and verify the signature appears.

Exporting, importing, and backing up signatures

• Press Windows+R, type %APPDATA%\Microsoft\Signatures, and press Enter.
• Copy the signature files (.htm, .rtf, .txt) to a backup location such as a USB drive or cloud storage folder.
• To import on another computer, paste the files into the same %APPDATA%\Microsoft\Signatures folder.
• Open Outlook, go to File → Options → Mail → Signatures…, and select the imported signature as the default.

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