How to add a signature in Outlook, client by client

How do you add a signature in the new Outlook for Windows?

Through the gear icon, in three clicks. Microsoft documents the path in its signature guide:

1. Select Settings (the gear icon, top right), then Accounts, then Signatures.
2. Select Add signature and give it a name.
3. Type the signature and format it: fonts, links and images are supported.
4. Use the checkboxes at the bottom to apply it to new messages, to replies and forwards, or to both.
5. Select Save.

If several accounts are connected, check which one is selected before you save: each account keeps its own signatures. The signature is stored in the Microsoft 365 mailbox, so it follows you to Outlook on the web. The new Outlook guide covers how to recover an old signature after the switch.

And in Outlook on the web?

The steps are the same as in the new Outlook, because both apps share the same settings: Settings > Accounts > Signatures, then Add signature. Older guides still mention Mail > Compose and reply; that is the previous layout.

An administrator cannot fill in this screen on behalf of employees. The PowerShell cmdlet that used to do it, Set-MailboxMessageConfiguration, no longer sets the signature while roaming signatures are on; the reasons and the workaround are in this guide.

Where is the signature setting in classic Outlook?

Under File > Options > Mail, Signatures button. In the window that opens:

1. Select New, name the signature, then build it in the Edit signature box (text, images, links).
2. Under Choose default signature, pick the e-mail account.
3. Choose the signature in the New messages list and in the Replies/forwards list.
4. Select OK.

Its editor is the most permissive of the four: tables, several images, any font installed on the PC. That is exactly why a signature built here can fall apart elsewhere. A font that only exists on your computer will be replaced on the recipient's side, and complex HTML does not render the same way on the web or on a phone. Missing images have six common causes.

Storage has changed. With a Microsoft 365 or Outlook.com mailbox and build 2303 or later, Microsoft says signatures in Outlook for Windows now roam across devices. Accounts on Exchange on-premises, POP or IMAP stay local and appear under "Signatures on this device". Roaming means a new laptop gets your signature back; it does not mean a colleague gets the same one.

How do you add a signature in Outlook for Mac?

From the Outlook menu in the menu bar, not from the message window. Microsoft's Outlook for Mac guide describes these steps:

1. Select Outlook > Settings (Preferences on older versions of macOS), then Signatures.
2. Add a signature, name it and type the content; pictures, links and tables are available in the editor.
3. Under the default signature options, pick the account, then the signature for new messages and for replies/forwards.
4. Close the window to save.

Labels differ slightly between the new and the legacy Outlook for Mac, and the legacy one no longer works with Microsoft 365 mailboxes since October 2026 (details in the Outlook for Mac signature guide). Either way, the Mac signature does not come from Windows or the web: it has to be created on the Mac. The Mac and mobile guide explains how to get the same signature on every device.

The four Outlook clients side by side

The mobile apps have their own field: Settings, then the account's signature, in plain text. By default they add "Get Outlook for [OS]" when no signature is set.

Should you add a business card (vCard) to your signature?

Usually not as an attachment. In classic Outlook, Microsoft explains how to include an electronic business card: place the cursor in the signature, select Business Card, then pick the contact. Outlook then inserts a picture of the card and attaches a .vcf file to every message sent with that signature.

That attachment is the problem. A .vcf on every email looks like an unexpected file to the recipient, adds a paperclip to every thread and repeats information already written in the signature. A link labelled "Add to contacts" or a QR code that opens the same vCard does the job without attaching anything; ATOM Signatures offers both as signature fields.

Is a digital signature the same thing as an email signature?

No. The email signature is the block with your name, title and logo. A digital signature (S/MIME) is a cryptographic proof: it shows the message really comes from you and was not altered on the way. Microsoft sums it up this way: S/MIME requires a certificate and certificate publishing infrastructure, configured in Exchange Online. It is an IT project, not a box to tick, and it makes sense where impersonation is a real risk: contracts, invoices, client files.

A third notion is often mixed up with the other two: the electronic signature on a document (a typed name, an image of a handwritten signature, a tool like DocuSign), which records agreement. None of the three replaces the others.

Why does every employee end up with a different signature?

Because Outlook treats the signature as a personal preference. Each person creates their own, in each client they use, and can change it whenever they like: remove a line, change the font, paste an old version. Roaming signatures sync one person's devices, never two people. Picture a sales rep who switched to Comic Sans, a Mac user still on last year's logo and a phone adding "Get Outlook for iOS" under all of it: nothing in Outlook prevents that.

To get the same signature for everyone, there are three realistic routes:

• A template and instructions. Fine for a handful of people, as long as someone checks every client after each change. It falls apart as the team grows.
• The admin tools built into Microsoft 365. A transport rule can add a disclaimer, and PowerShell no longer sets the signature while roaming signatures are on. The native Microsoft 365 options compare their limits.
• A signature management tool. The template is defined once and each employee's details come from the Microsoft 365 directory. The organization-wide deployment guide details the steps.

ATOM Signatures takes the third route with an Outlook add-in deployed from the Microsoft 365 admin center: the signature is inserted while the message is being written, visible in the draft, on Windows, Mac, the web, iPhone and Android. Email is never rerouted through a third-party server. The add-in can also switch between an internal and an external signature based on the recipients, something Outlook does not do on its own (internal vs external signature). If you also want to stop employees from changing their signature by hand, the client-by-client guide lists what each Outlook allows. The free tools check an existing signature before you change anything.

Frequently asked questions