Mailtiv

Ways to manage email signatures in Microsoft 365

Updated 4 November 2026 by the Inthouse product team

There's no single right way to run company email signatures. The choice depends on where you want the signature added, whether your email may leave Microsoft 365, and how much it matters that people see their signature while they write.

The four approaches

1. Outlook's own signatures

Each person creates their signature in Outlook settings. It's free and needs no setup. But keeping every signature consistent, with current titles and phone numbers, is up to each person. You can't change them centrally or add a campaign.

2. Exchange mail-flow rules

IT creates a rule (a disclaimer) in Exchange Online that adds text to outgoing email. The signature is central and is added to email sent from any device. But it's added on the server after the email is sent, so people don't see it while they write. In replies it lands at the bottom of the whole thread. Design options are limited, and the rules get harder to manage as they multiply.

3. Server-side signature services

After outgoing email leaves Microsoft 365, it's routed through the provider's servers, which add the signature. This usually works on every device, and design options are broad. In return, your email passes through a third-party infrastructure, and an extra connector is set up in Exchange for it. Whether people see the signature while writing depends on the service.

4. Outlook add-ins

An add-in inserts the signature while the person writes in Outlook, so they see it before sending. Mail flow doesn't change; your email stays inside Microsoft 365. Which Outlook versions and devices an add-in works on depends on what Microsoft allows add-ins to do. This is the approach Mailtiv uses.

Side by side

Where Mailtiv fits

Mailtiv is an Outlook add-in and web portal. You design signatures centrally in the portal; the add-in inserts the right one while people write.

• Your email never passes through Mailtiv. Mailtiv doesn't read, store or route your messages. No extra connector is needed.
• Where it works: new and classic Outlook for Windows, Mac, Outlook on the web, and iPhone/Android. On phones, signatures are added to emails but not to meeting invites.
• Meeting invites: on computers and the web, meeting invites get a signature too.
• Not supported: one-time-purchase Outlook 2016 and 2019 can't add signatures automatically.
• Central control: assign signatures to departments and Mailtiv groups, and switch them for a period with dated campaigns.
• Personal details: name, title, phone and photo come from each person's own Microsoft 365 profile.
• Setup: a Global Admin approves Mailtiv once in Microsoft 365 and deploys the add-in from the Microsoft 365 admin center. See Set up Mailtiv.

For how Mailtiv works and what data it uses, see How Mailtiv works.

How to choose

Ask these questions before you decide:

1. Is it acceptable for our email to pass through infrastructure outside Microsoft 365? Check this against GDPR, KVKK and your own security policies.
2. Should people see the signature before they send? Seeing it while writing makes a wrong signature easy to spot.
3. Which Outlook versions and devices do we use? Older one-time-purchase versions and phones don't behave the same under every approach.
4. Do meeting invites need a signature too?
5. Do we want different signatures by department, or seasonal campaigns?
6. Who will set it up and look after it? Writing rules, setting up a connector and deploying an add-in are different kinds of work.
7. Where will the personal details come from? If your Microsoft 365 profiles are kept up to date, signatures stay up to date too.

Frequently asked questions

What's the main difference between a server-side signature and an Outlook add-in?

With a server-side service, the signature is added on the service's servers after the email is sent, so your email passes through those servers. With an Outlook add-in, the signature is added in Outlook while the person writes, and the email stays inside Microsoft 365.

Aren't Exchange mail-flow rules enough?

For a simple, mostly text signature they can be. They fall short if you want people to see their signature while writing, the signature in the right place in replies, or different designs per department.

Do Outlook add-ins work on phones?

It depends on the add-in. Mailtiv adds signatures to emails in Outlook for iPhone and Android; on phones, meeting invites don't get a signature.

Does Mailtiv read or store our email?

No. Mailtiv fills the signature from each person's Microsoft 365 profile and puts it into the email in Outlook. Your email never passes through Mailtiv; it isn't read, stored or routed.

Can we combine approaches?

You can, but the same email may then get two signatures. If you use Mailtiv, turn off people's own Outlook signatures and review any mail-flow rules that add a signature. See Set up Mailtiv.