Outlook roaming signatures: why signatures disappear or won't sync, and how admins turn it off

What roaming signatures are, and which Outlooks use them

Microsoft: "Email signatures in Outlook for Windows now roam across devices." With the feature on, "signatures will be stored in the user's mailbox", not in files on one PC. "This feature is available for Outlook build 2303 or higher."

• Which mailboxes: "mailboxes on Microsoft 365 or Outlook.com". Accounts "hosted on Exchange on-premises servers, with third-party email services, or utilizing POP/IMAP accounts will not be able to roam their signatures at this time."
• Which Outlooks: classic Outlook for Windows from build 2303, plus Outlook on the web and new Outlook for Windows, which Microsoft's admin documentation says use roaming signatures too.
• Not covered: Microsoft's roaming article doesn't mention Outlook for Mac or the Outlook apps for iPhone and Android.

Users don't switch it on: when the feature reached a PC, the signatures "selected as default for New messages or Replies/forwards" were copied to that account's mailbox, and "No existing signatures will be overwritten". The others stayed on the PC, listed under Signatures on this device: you can still insert them, but you can't edit them until you link them to an account.

To see which Outlook you have, Microsoft's test is the Settings gear in the top right: "If you have the Settings button, you have the new Outlook." In classic Outlook, choose File › Office Account; "The Outlook version and build number is under Product Information."

A signature gone after an update

Microsoft's known issue "Signatures are not syncing between Outlook Desktop and Outlook Web App" describes it: in classic Outlook, "the newly created signature gets deleted after a while", or it doesn't reach Outlook on the web. The cause, in Microsoft's words: "Outlook checks to see if the signatures that we have on the PC match the list of signatures in the roaming_signature_list." When a new signature isn't in that list "shortly after a sync up, Outlook deletes it."

The page says "STATUS: FIXED" (last updated November 6, 2024), with these first fixed versions:

From Microsoft's known-issue page, read on 5 November 2026.

So: check your build (File › Office Account), update Outlook if it is older, and make the signature again. If it still disappears, Microsoft's workaround, which we haven't run, is to close Outlook, rename the registry key HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Settings to Settings_old, and restart Outlook. Microsoft explains that "Account data related to Cloud Settings is cached under the Settings key."

A signature that is gone only from your other devices may be one that never roamed: look for it under Signatures on this device on the PC where you made it. To make it again in a minute, use the builder at the end of this page.

Not syncing between desktop, web and phone

• The mailbox doesn't roam. An Exchange server at your company, a third-party email service, or a POP or IMAP account keeps its signatures on each device. Set the signature up in every Outlook you use.
• Classic Outlook is older than 2303, or older than the fixed build above.
• The signature is under Signatures on this device. Link it to your account in classic Outlook's signature settings, or make it again in Outlook on the web.
• Your admin turned roaming off, with one of the switches below. Then each Outlook keeps its own signature.
• The phone. Microsoft's steps for Outlook for iOS and Android are in the app: "Open Settings." "Under Mail, tap Signature." The page says nothing about syncing with the computer, so set it there too. The Outlook app guide covers adding a logo on the phone.

Microsoft's own signature page still says that "if you have a Microsoft account, and you use Outlook and Outlook on the web", "you need to create a signature in both products." Whatever your setup, the check is the same: open the signature settings in each Outlook you use, and send yourself a test from each.

Admins: turn off roaming for Outlook on the web and new Outlook

The switch is a setting of the whole organization, in Exchange Online. Microsoft: "The PostponeRoamingSignaturesUntilLater parameter controls whether roaming signatures are enabled or disabled in Outlook on the web (formerly known as Outlook Web App or OWA) and the new Outlook for Windows." With $true, "Roaming signatures are disabled for Outlook on the web and the new Outlook for Windows." $false turns them back on and is the default.

1. With the Exchange Online PowerShell module installed, open PowerShell and run Import-Module ExchangeOnlineManagement.
2. Connect with your admin account: Connect-ExchangeOnline -UserPrincipalName admin@yourcompany.com, and sign in.
3. Run Set-OrganizationConfig -PostponeRoamingSignaturesUntilLater $true.
4. When you're finished, run Disconnect-ExchangeOnline.

What it does and doesn't do:

• Classic Outlook isn't covered. Microsoft: "For Windows clients, the registry setting to disable roaming signatures still works." That is the next section.
• Admin-set signatures work again. With roaming off, Microsoft says admins can use Set-MailboxMessageConfiguration with AutoAddSignature, AutoAddSignatureOnReply and SignatureHtml. Each of those parameters "doesn't work if the Outlook roaming signatures feature is enabled". SignatureHtml sets the signature for HTML messages in Outlook on the web, and "To automatically add this email signature", AutoAddSignature "must be set to $true".
• No Graph API. Microsoft: "We have no plans to support roaming signature management in the Microsoft Graph API." It points signature tools to an Outlook add-in signature API instead.

Classic Outlook: the registry setting

For one PC, add a DWORD value under the current user's Outlook setup key:

Key:   HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Setup\
    Value: DisableRoamingSignatures   (DWORD)
    Data:  1

Microsoft: "setting it to 1 will disable the feature and prevent signature migration upon rollout." For many PCs, admins "can choose to use its corresponding Group Policy location to the same effect": the same DWORD value under HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Office\16.0\Outlook\Setup.

One reason to set it, from Microsoft's article: add-ins that set signatures by changing each PC's files and registry stop working with roaming on. Microsoft: "these add-ins will no longer work when this feature is enabled."

One signature for the whole team

Roaming moves one person's signature between their own Outlooks. It doesn't give the team the same signature: each person still makes their own, unless an admin turns roaming off and sets signatures with SignatureHtml, which Microsoft describes as an Outlook on the web setting. For one person, or a small team pasting their own, make the signature once below and paste it into Outlook on the web.

Then, from Microsoft's steps for Outlook on the web (new Outlook for Windows has the same steps):

1. Press Copy signature above.
2. In Outlook on the web, select Settings at the top of the page, then Accounts › Signatures.
3. Select Add signature, give it a name, click in the editing box and paste.
4. Use the checkboxes at the bottom to add it to new messages and to replies and forwards, then select Save.
5. Open classic Outlook, if you use it: File › Options › Mail › Signatures. With roaming on, the signature should be listed for your account. If it isn't, paste it there too.
6. Send a test to an address outside your company and look at it there.

We haven't pasted this signature into a Microsoft 365 mailbox; the test email is the check. The logo is loaded from its link, so a reader whose app blocks pictures sees the company name until they allow them: why a signature logo isn't showing explains each app.

For 5 or 50 people, this is where pasting stops working: each person repeats the steps in each Outlook, and a new phone number or logo means asking everyone to do it again. The team signature guide shows what Microsoft 365 and Google Workspace admins can set for everyone, and email signature tools compared lists the paid services.

Questions

Why does my Outlook signature keep disappearing?

In classic Outlook for Windows with roaming signatures, a known issue deleted a new signature when it didn't appear in the mailbox's list of roaming signatures shortly after a sync. Microsoft marks it fixed, from Version 2410 (Build 18129.20124) on Current Channel. Update Outlook and make the signature again; Microsoft also gives a registry workaround, renaming Outlook's Settings key to Settings_old and restarting Outlook.

How do I disable roaming signatures in Outlook?

There are two switches. For Outlook on the web and new Outlook, a Microsoft 365 admin turns roaming off for the whole organization with one Set-OrganizationConfig setting in Exchange Online PowerShell; the command is on this page. For classic Outlook for Windows, set the DWORD value DisableRoamingSignatures to 1 in the current user's Outlook Setup key in the registry, or in its Group Policy location. The exact keys are on this page.

Why doesn't my Outlook signature sync to my phone?

The Outlook app for iPhone and Android has its own signature: Settings, then Signature under Mail. Microsoft's roaming signatures article covers Outlook for Windows and doesn't mention the phone apps, so set the signature up in the app as well.

Sources

• Microsoft: Outlook roaming signatures: build 2303, supported mailboxes, Signatures on this device, DisableRoamingSignatures. Read on 5 November 2026.
• Microsoft known issue: Signatures are not syncing between Outlook Desktop and Outlook Web App: status fixed; last updated November 6, 2024. Read on 5 November 2026.
• Microsoft Learn: Set-OrganizationConfig: the parameter that turns roaming off for Outlook on the web and new Outlook. Read on 5 November 2026.
• Microsoft Learn: Set-MailboxMessageConfiguration: SignatureHtml and AutoAddSignature. Read on 5 November 2026.
• Microsoft Learn: Connect to Exchange Online PowerShell. Read on 5 November 2026.
• Microsoft: Create and add an email signature in Outlook. Read on 5 November 2026.
• Microsoft: What version of Outlook do I have?. Read on 5 November 2026.
• Microsoft: Can I change my email signature? (Outlook for iOS and Android). Read on 5 November 2026.