How to Add an Email Signature in Outlook (New Outlook, Classic, Web, Mobile) – 2026

To add an email signature in Outlook, open the signature settings for your version and paste or type the signature there: Settings > Accounts > Signatures in the new Outlook for Windows and Outlook on the web, File > Options > Mail > Signatures in classic Outlook, and Settings > Signature in the Outlook mobile apps. Each version has its own editor and its own rules about what syncs, so a signature made in one place does not always appear in the others.

Who this is for and what you will have at the end

This guide is for anyone who sends email from Outlook with a Microsoft 365, Outlook.com or other account, and for the person in a small business who ends up setting signatures up for everyone else. At the end you will have:

• a signature added to every Outlook you use, set as the default for new messages and for replies and forwards;
• an understanding of which signatures sync between devices and which don't;
• a clear view of the three ways to apply one signature to a whole Microsoft 365 organization, and the limits of each.

The menu paths below come from Microsoft's current support and Learn pages, listed in the references at the end.

Before you start: build the signature once

The Outlook signature editors are simple rich-text boxes. They don't accept pasted HTML source code, and they make it easy to end up with a picture embedded inside the signature, which some email apps strip and others send as an attachment. The reliable approach is:

1. Build the signature once, as a web page, with any images (logo, headshot, social icons) loaded from public https addresses.
2. Copy the rendered signature, the way you would copy formatted text from a web page.
3. Paste it into each Outlook signature editor.

The free EpiFive email signature generator does steps 1 and 2 in your browser: it writes table-based HTML with inline styles (the kind that classic Outlook and Gmail display correctly), checks that every image is a hosted link with a width and height, and has a Copy signature button for pasting into Outlook. If you prefer to type the signature directly in Outlook, that works too; keep it to text and links, and insert the logo from a hosted address where the editor allows it.

Keep the signature short. A name, job title, company, one or two phone numbers, the email address, the website and, if needed, a one-line disclaimer is enough. Long legal text and large images make every reply in a thread longer, and many recipients read on a phone.

New Outlook for Windows

The new Outlook for Windows uses the same signature screens as Outlook on the web. According to Microsoft's "Create and add an email signature in Outlook" page:

1. Select Settings (the gear icon).
2. Select Accounts > Signatures.
3. If you have more than one account in the new Outlook, select the account the signature is for.
4. Select Add signature and give it a distinct name.
5. In the editing box below the name, paste or type your signature and format it.
6. Use the checkboxes at the bottom to apply it to new messages and to replies and forwards, or leave them clear and insert the signature by hand.
7. Select Save.

To insert a signature by hand while writing, select New mail, then on the Message tab, in the Insert group, select Signature and choose one of your saved signatures. Signatures... at the bottom of that list opens the signature settings.

You can keep several signatures, for example a full one for new external emails and a short one for replies, and set each as the default for one type of message.

Classic Outlook for Windows

Classic Outlook (the Outlook that comes with Microsoft 365 Apps) has a separate dialog box:

1. Open a new email message.
2. On the Message menu, select Signature > Signatures. You can also reach the same dialog from File > Options > Mail > Signatures.
3. In the E-mail account list, choose the account. Each account can have its own signature.
4. Under Select signature to edit, choose New, then type a name in the New Signature dialog box.
5. Under Edit signature, paste or type your signature.
6. Under Choose default signature, set the New messages list and the Replies/forwards list to your signature, or leave them at (none).
7. Select OK.

Microsoft notes one surprise: the message you opened in step 1 does not get the new signature, even if you set it as the default for new messages. Add it to that one message by hand from Message > Signature.

To add a logo in classic Outlook's editor, use the image button in the signature editor, then right-click the image, choose Picture and use the Size tab to resize it. A logo inserted from a file this way is stored with the signature, which is exactly the kind of embedded image that can turn into an attachment for some recipients. Pasting a signature whose logo loads from a hosted https link avoids that.

Where classic Outlook keeps signatures

Classic Outlook used to keep signatures only on the computer where they were created. With roaming signatures, Microsoft now stores them in the mailbox. Microsoft's roaming signatures page says the feature:

• is available for Outlook for Windows build 2303 or higher, with mailboxes on Microsoft 365 or Outlook.com;
• turns on automatically and does not overwrite existing signatures;
• copies only signatures that are set as defaults for New messages or Replies/forwards to the mailbox when it migrates them;
• leaves other signatures under Signatures on this device, available only on that computer;
• does not support Exchange on-premises servers, third-party email services or POP/IMAP accounts.

So if a signature is missing on your second PC, check that it is set as a default on the first one, or recreate it.

Outlook on the web and Outlook.com

Outlook on the web (outlook.office.com for work and school accounts) and Outlook.com use the same steps as the new Outlook for Windows: Settings > Accounts > Signatures, then Add signature, name it, paste or type it, tick the boxes for new messages and replies or forwards, and select Save. To add a saved signature by hand, use Signature on the Message tab while writing.

With a Microsoft 365 mailbox and roaming signatures switched on (the default), signatures you save here and in the new Outlook for Windows are stored in the mailbox. Microsoft's own page still advises that if you use both Outlook and Outlook on the web with a Microsoft account, you may need to create the signature in each, so check both after you save.

Outlook for iOS and Android

The mobile apps don't pick up your desktop or web signature. Microsoft's Outlook mobile help gives these steps for both iOS and Android:

1. Open Settings (tap your profile picture at the top left, then the gear icon).
2. Under Mail, tap Signature.
3. Enter your signature, or turn on Per Account Signature to give each account its own.

The mobile editor is much simpler than the desktop ones. A pasted signature with a table layout and images may lose its columns or pictures, so a compact, mostly text signature works best on phones. One practical way to get a formatted signature onto the phone is to email it to yourself, open that email in the Outlook app, copy the signature and paste it into the Signature screen; check the result by sending yourself a test message.

Which signature appears where

If you change your phone number or job title, update every row that applies to you. Keeping a master copy of the signature as a file makes this a two-minute job.

Company-wide signatures in Microsoft 365

Per-user signatures depend on each person pasting the right version into every app, and they drift: one person's mobile number is old, another uses last year's logo. Microsoft 365 offers three ways for an admin to take control, each with trade-offs.

Option 1: a mail flow rule that appends a disclaimer

An Exchange Online mail flow rule (also called a transport rule) can add HTML text to the top or bottom of messages as they pass through the service. Microsoft's Learn article on organization-wide disclaimers describes these steps in the Exchange admin center:

1. Go to Mail flow > Rules at admin.exchange.microsoft.com.
2. Select Add a rule, then Apply disclaimers.
3. Name the rule. Under Apply this rule if, choose The recipient > is external/internal and select Outside the organization, or Apply to all messages.
4. Under Do the following, keep Apply a disclaimer to the message with append a disclaimer (or choose prepend a disclaimer to put it at the top), then select Enter text and enter the signature as HTML.
5. Select the fallback action for messages the rule can't change.
6. Under Except if, add The subject or body > Subject or body matches these text patterns with a phrase from your signature, so it isn't added again on every reply in a thread.
7. Choose Enforce, or Test without Policy Tips to log results first, then finish the wizard.

The text can include HTML, inline CSS and images through the IMG tag, plus tokens that Exchange fills in from the sender's directory details, including %%DisplayName%%, %%Title%%, %%Department%%, %%Company%%, %%Phone%%, %%MobilePhone%% and %%WindowsEmailAddress%%. Microsoft's PowerShell example for an external-only rule is:

New-TransportRule -Name "External Disclaimer" -SentToScope NotInOrganization -ApplyHtmlDisclaimerText "<h3>Disclaimer Title</h3><p>This is the disclaimer text.</p><img alt='Contoso logo' src='http://www.contoso.com/images/logo.gif'>"

The limits matter before you choose this as your signature system:

• The sender never sees it. The rule changes the message in transit, after the sender has finished writing, so there is no signature in the compose window to check or edit.
• Placement is all or nothing. The text goes at the very top or the very bottom of the message. In a reply, an appended signature lands under the whole quoted conversation, not under the new text.
• Repeats need an exception. Without the Except if text pattern, a long thread collects one copy per message.
• Directory data must be complete. A token for an empty attribute produces an empty value, so a missing mobile number leaves a bare label unless you design around it.
• Some messages can't be changed. For messages the rule can't modify, such as encrypted ones, you choose a fallback: Wrap (the default) puts the original message inside a new message as an attachment, Ignore delivers it without the disclaimer, and Reject returns it to the sender. Microsoft warns not to use Wrap in rules that affect incoming messages from external senders, because it interferes with Safe Attachments scanning.

For a legal disclaimer that must be on every external email, a mail flow rule is a good fit. As a person's signature, these limits are why many organizations look elsewhere. The EpiFive article on organization-wide email signatures in Microsoft 365 compares the approaches in more detail.

Option 2: set each mailbox's signature with PowerShell

Set-MailboxMessageConfiguration has SignatureHtml, AutoAddSignature and AutoAddSignatureOnReply parameters that set a mailbox's signature for Outlook on the web. The catch is roaming signatures. Microsoft's reference for each of these parameters says it doesn't work if the Outlook roaming signatures feature is enabled in your cloud-based organization, which it is by default.

Admins can turn roaming signatures off for Outlook on the web and the new Outlook for Windows with:

Set-OrganizationConfig -PostponeRoamingSignaturesUntilLater $true

Microsoft's Set-OrganizationConfig reference says $true disables roaming signatures for those two clients and lets admins use the Set-MailboxMessageConfiguration signature parameters again, while $false is the default. For classic Outlook on Windows, the registry setting from the roaming signatures page still applies: a DWORD named DisableRoamingSignatures set to 1 under HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Setup\. The same page notes that signature add-ins which change local files or the registry stop working when roaming signatures are on.

The same reference adds that Microsoft has no plans to support roaming signature management in the Microsoft Graph API, and recommends that independent software vendors use the signature API with event-based activation instead. PowerShell signatures also don't reach classic Outlook or the mobile apps, so this option suits organizations that mostly use Outlook on the web.

Option 3: an Outlook add-in with event-based activation

The route Microsoft points vendors to is an Outlook add-in that runs when a message is created. Event-based activation lets an add-in run in the background on the OnNewMessageCompose event, which covers new messages, replies and forwards. Microsoft lists support for it in Outlook on the web, the new and classic Outlook on Windows, the new Outlook on Mac, and Outlook on Android and iOS (the Mac and mobile versions need the add-in only manifest). Microsoft publishes a sample, "Set your signature using Outlook event-based activation", and the setSignatureAsync method inserts the signature into the message the user is writing.

Two deployment details are worth knowing. Event-based add-ins launch automatically only when an admin deploys them, which is done in the Microsoft 365 admin center under Settings > Integrated apps > Upload custom apps, or when the add-in has an unrestricted Microsoft Marketplace listing. And because the signature is inserted while the user writes, they see it, it sits in the normal signature position under their new text, and it is in their Sent Items like any other content.

Comparing the three

Troubleshooting

• Images arrive as attachments or as red crosses. The image is embedded in the signature, or its link isn't public. Load images from a public https address that opens the image itself without signing in.
• The signature is missing from replies. Set a default for Replies/forwards (classic Outlook) or tick the replies and forwards box (new Outlook and Outlook on the web).
• The signature is missing on another PC. In classic Outlook, only default signatures roam; others stay under Signatures on this device.
• Set-MailboxMessageConfiguration runs without errors but nothing changes. Roaming signatures are on in the organization; see Option 2.
• The mail flow disclaimer repeats down a long thread. Add the Except if text pattern from Option 1.
• Some emails arrive as an attachment inside a new message. A mail flow disclaimer rule with the Wrap fallback met a message it couldn't change, such as an encrypted one.

Checklist

• Build the signature once, with hosted https images, and keep a master copy.
• Add it to every Outlook you use: new Outlook or Outlook on the web, classic Outlook, and each phone.
• Set it as the default for new messages and for replies and forwards.
• Send yourself a test email and open it on a computer and a phone.
• For a whole organization, decide between a mail flow rule (legal text, server side), PowerShell (Outlook on the web, roaming postponed) and an event-based add-in (signature visible while writing, on desktop, web and mobile).

What we checked

• Opened Microsoft's "Create and add an email signature in Outlook" support page on 2026-11-10 and copied the menu labels for the new Outlook (Settings, Accounts > Signatures, Add signature, Save) and classic Outlook (Message > Signature > Signatures, Select signature to edit, New, Edit signature, Choose default signature, New messages, Replies/forwards); the page confirms the new Outlook and web steps are the same.
• Opened the Outlook roaming signatures support page on 2026-11-10 and confirmed build 2303 or higher, Microsoft 365 or Outlook.com mailboxes, that only default signatures migrate, and the registry path and DWORD name DisableRoamingSignatures with value 1.
• Opened Microsoft's Outlook mobile help page "Can I change my email signature?" on 2026-11-10 and copied the steps (Settings, Mail, Signature, Per Account Signature).
• Opened the Exchange Online Learn article on organization-wide disclaimers (updated 2026-08-03 per its metadata) and copied the Exchange admin center steps, the list of sender tokens, the PowerShell example exactly as published, and the Wrap, Ignore and Reject fallback descriptions.
• Read the Set-OrganizationConfig reference source for PostponeRoamingSignaturesUntilLater and the Set-MailboxMessageConfiguration reference for SignatureHtml, AutoAddSignature and AutoAddSignatureOnReply, and cross-checked that both describe the roaming signatures restriction the same way.
• Opened Microsoft's event-based activation article (updated 2026-09-01) and confirmed the OnNewMessageCompose client list, the manifest note for Mac and mobile, and the admin deployment path (Settings > Integrated apps > Upload custom apps).
• Not checked: we did not create a mail flow rule, change roaming signatures or deploy an add-in in a live tenant, and the iOS and Android steps were not tested on a device. The steps follow Microsoft's documentation as of 2026-11-10.

Last tested: 2026-11-10

References

• Create and add an email signature in Outlook (Microsoft Support)
• Outlook roaming signatures (Microsoft Support)
• Can I change my email signature? Outlook for iOS and Android (Microsoft Support)
• Organization-wide message disclaimers, signatures, footers, or headers in Exchange Online (Microsoft Learn)
• Set-MailboxMessageConfiguration (Microsoft Learn)
• Set-OrganizationConfig (Microsoft Learn)
• Activate add-ins with events (Microsoft Learn)
• Office.Body setSignatureAsync (Microsoft Learn)