Outlook on the web signature not saving? Check these first

A signature in Outlook on the web goes into new emails only when its new-messages checkbox is ticked, and into replies and forwards only when its replies-and-forwards checkbox is ticked. If both boxes are set and the signature still does not appear, insert it by hand from the Message tab. If the new message window will not open at all, the signature HTML probably contains characters Outlook cannot parse.

Check the signature settings first

1. Select the Settings gear at the top of the page.
2. Select Accounts, then Signatures.
3. Select the pencil (Edit signature) next to your signature, or Add signature for a new one.
4. Tick the boxes at the bottom: one for new messages, one for replies and forwards. Leave both blank if you want to add the signature by hand.
5. Select Save.

Microsoft's page describes these boxes only as "at the bottom of the editor," so the labels may differ on your screen. Some Q&A answers describe a path of Settings, View all Outlook settings, Mail, Compose and reply. Use whichever path matches your screen.

If you have a Microsoft account and use both Outlook and Outlook on the web, Microsoft says you need to create a signature in both. The account choice and the reply-only setup are covered in the reply signature guide.

Insert it by hand to test

In a new message, select Message, then Signature, and choose the signature. Microsoft documents this step for signatures that are not added automatically.

• If it appears, the checkbox or the account is the problem, so go back to the settings above.
• If it does not appear, or the box stays empty, the signature content is the problem. Go to the next section.

When the new message window will not open

Microsoft's knowledge base article describes a case where selecting New in Outlook on the web opens no message window. The cause it gives is special characters in the signature. Its example is a signature full of raw HTML tags and stray backslashes, such as <span style=\"font-family:...\">.

The fix in Microsoft's article is to remove the signature, open a new message, and then keep the signature simple, with no special characters. The example is raw code, so check whether your signature box holds code instead of formatted content. Paste formatted content, then check that a new message window opens.

Admins: roaming signatures can block a PowerShell signature

Microsoft's Set-MailboxMessageConfiguration page says the SignatureHtml parameter for Outlook on the web does not work when Outlook roaming signatures are enabled in a cloud-based organization. The same page says admins can temporarily disable roaming signatures with the PostponeRoamingSignaturesUntilLater parameter on Set-OrganizationConfig.

Microsoft's roaming signatures page describes the feature for Outlook for Windows and gives a different way to disable it, with a DisableRoamingSignatures registry value. The two pages do not describe the same clients, so the exact clients affected by the cmdlet limit are not confirmed. Before you push a PowerShell signature to everyone, set one account in the browser, then check that it appears in a new message.

Browser problems

A 2021 Microsoft Q&A thread describes a user whose signature showed in Edge and Internet Explorer but not in Chrome. A Microsoft moderator tested Chrome 95 and reported that the signature loaded for new messages and replies. The workaround in that thread: when a reply or forward does not get the signature, select the ... button and choose Insert signature.

A 2025 answer on another thread suggests clearing the browser cache and cookies, then signing out and back in. Try a second browser or a private window first, so you know whether the fault is the browser or the account.

How Sendoff handles this

Sendoff builds the signature with tables and inline styles. The Copy button writes it to the clipboard as HTML and as plain text, so paste the result into the editor and leave the code out. Sendoff also has an Outlook add-in. Its page says the add-in runs when someone starts a new email and inserts their signature, and that it works in Outlook on the web. If the built-in boxes keep failing, the add-in is the option to try. Setup steps are on the Outlook integration page.

Sources

• Microsoft Support, create and add a signature in Outlook on the web: https://support.microsoft.com/en-us/office/5ff9dcfd-d3f1-447b-b2e9-39f91b074ea3
• Microsoft Learn, Cannot create a new message from Outlook Web App: https://learn.microsoft.com/en-us/troubleshoot/exchange/outlook-on-the-web-issues/cannot-create-new-message-in-owa
• Microsoft Learn, Set-MailboxMessageConfiguration: https://learn.microsoft.com/en-us/powershell/module/exchange/set-mailboxmessageconfiguration
• Microsoft Support, Outlook roaming signatures: https://support.microsoft.com/en-us/office/outlook-roaming-signatures-420c2995-1f57-4291-9004-8f6f97c54d15
• Microsoft Q&A, Chrome signature thread (2021): https://learn.microsoft.com/en-us/answers/questions/606502/outlook-365-web-version-not-displaying-signatures
• Microsoft Q&A, signature not included in emails (2025): https://learn.microsoft.com/en-us/answers/questions/5609418/my-email-signature-is-not-included-in-my-emails
• Microsoft Q&A, OWA signature through PowerShell (2022): https://learn.microsoft.com/en-us/answers/questions/944234/unable-to-change-owas-signature-through-powershell