Signature management?

Occasional Contributor

Im not sure if this is the right place discuss this, but ill give it a shot.


Im developing an internal application that leverages Azure Active directory for identity management, and Office 365 for mail and calendar (via the graph api). My goal is to manage the signature for all my users via some kind of API also. All my google skills cannot turn up any definitive answer on this topic, not even how to manage it through some admin-panel. This surely must be a thing!? The only solution ive seen is to use a discalimer transport rule (that only can be appended to the end of emails, and cannot feature per-user images, and the user cannot see this signature).


Surely office 365 can have a centrally managed signature, thats appended to any platform using it. Do i have the wrong product (Office 365 Business Essentials for testing purposes)? Am i missin some administration panel?


A company with thousands of employees - how do they manage email signatures? Send some guy to open their email clients on all devices and type them in? Copying and pasting images and what-not. What am i missing?

14 Replies

Easy answer, no there isnt a built in way to manage signatures like this - you have to go 3rd party providers in general


The APIs should allow you to set signatures in OWA on a per user basis, and then you have to come up with some kind of way to set them in the Outlook client, maybe client install, or group policy or something similar.

Thank you for the promt reply, and insight into the problem. Great to hear from someone with experience. I cannot find any endpoints for the OWA signatures. There is a new mailboxSettings object in Graph/o365 api but that just contains autoresponses.


How are the third party providers doing it? My development team must be able to implement a similar solution as anyone else, or are the third party providers bying into some other kind of access to my tenant/exchange?


heres the settings object for anyone looking:



Hi Robert,

One such provider is Exclaimer which provide a signature service. To work with exclaimer you have to route your mail through to their servers so I think it's a more complex deployment and not something that leverages the REST API (Though I'm not 100% sure just my opinion)
Transport rules are the best option to natively provide a corporate signature.

I guess different companies have different expectations, but per user images in a signature would be pretty odd looking if you ask me, signatures should be neat and precise, and only on external messages.

Thank you for providing me with a third party example. Looking at their specs ( it would seem like they are parsing the emails "on the way out", and would not show the signature to the actual user in their respective client. I wonder if they try to parse the content to insert it before any quoted mails, and how successful they are in this.
Thank you for for providing some feedback. Transport rules indeed seems like the only solution right now, with the three drawbacks i mentioned earlier
- only appended to the end of emails, after quoted mails
- cannot feature per-user images (maybe solved with some hacky base64encoded-field workaround)
- the user cannot see the signature, and hence the "entirety" of the mail/communicaiton is unknown (for example i have a signature with a "Best regards" phrase in my native language, while i sometimes swap it for other languages, or change phrasing depending on the situation)

Value judgements on the contents and design of the signatures i leave to my enterprise - i just implement solutions ;)

Im very surprised that this isnt a huge button front and center of the o365 portal that says "manage signatures"
This provides a more client centric approach

Code Two also provide centralized control over email signatures: 


Generally speaking, you can approach the problem in three ways:


1. Let the users do their own thing - provide them with a prototype signature file on a periodic basis and ask them to update via Outlook/OWA. This is quick, cheap, and users can modify the signature. However, it doesn't ensure consistency and users are prone to forget to apply the update.


2. Use Exchange Transport Rules - you will be guaranteed that signatures are stamped on all outgoing messages and if your Active Directory is correctly populated with the attributes you want to include (like phone number), the outbound signature will be complete. The advantage of this approach is a guaranteed consistency in signatures. The downside is that users don't get to vote and that they might add their own signature to the mix. Also, remember that ETRs can't process signed or encrypted messages.


3. Use a commerical product - you pay for someone else to do all the development, but you get the advantages of years of experience and tons of experience gained from other customer engagements. If signature consistency is important to you, this is the route you should take.



Late Reply, but I have done a similar project recently


We handle outlook from group policy logon scripts

OWA is handled through POweshell from which we upload the signature of the user

mobile clients (Android etc) we are also looking for a solution

Super late to the party, but the new announcement about roaming signatures hints at an API that will be published to manage these signatures. See the very bottom of

@Robert Gøransson 


Cloud based, just share a link and let staff do the rest

@Robert Gøransson big companies use a professional email signature management tool. The main condition must be Microsoft 365 integration. Then you just create a "Master" signature and, with a few clicks, integrate employees' contact information to get ready standardized email signatures. A fantastic Microsoft 365 Email Signature Management Solution you can find in Newoldstamp.