How to create an​d set up​ Microsoft Office 365/Outlook email signatures

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Since its launch in 2011, Office 365 (Microsoft 365) has become one of the top cloud productivity suites used by businesses worldwide.  

If you’re moving to, or are already on, Microsoft’s cloud platform, it’s important to implement an Office 365 email signature template for all users. When done correctly, a professional Office 365 signature setup will make a positive impression on your audiences. So, this can’t be left in the hands of your end users.  

For IT admins, this usually involves creating an email signature in Office 365 using a transport rule and the native disclaimer function. But how do you do this? 

In this guide, we’ll show you how to create an Office 365 email signature within Exchange Online step-by-step. All you need to do is follow these instructions below. 

Requirements for creating an Office 365 email signature

Before we get started, ensure you have the following:

  • An active Office 365 subscription

  • Admin access to your Office 365 account

  • A web browser (preferably Google Chrome or Microsoft Edge)

  • Optional: an HTML editor for coding your signature design

How to create and set up a custom Office 365 email signature 

 Important: This can be very time-consuming. To create professional email signatures more easily, consider using our Office 365 email signature management solution. 

1. Design your default email signature in either HTML or plain text. For tips on what to include in a professional email signature, read How to Write Professional Email Signatures (With 20+ Examples). 

2. Add Active Directory (AD) attributes to your template. These are special tags that add unique elements from each user’s Active Directory account.

Examples include:

  • DisplayName

  • FirstName

  • LastName

  • PhoneNumber

  • Email

Enclose each attribute name with two percentage signs such as %%DisplayName%%.  

Note: This only works if your Active Directory is up-to-date and complete in terms of all user attributes. Otherwise, you could end up with incomplete email signatures that look unprofessional. 

For a full list of AD attributes, check out this TechNet article. 

3. Save the finished template as a TXT file. 

4. Open a web browser and enter the URL https://portal.microsoftonline.com 

Login into Office 365 to create your email signature


5. Enter the username and password for your organization’s Microsoft 365 tenancy ID. 

6. From the Home screen in Exchange Online, click the icon on the top right of the screen. Choose the Admin icon. 

Choose the Office 365 admin center


7. You’re presented with the Microsoft 365 admin center home screen. Click on the Exchange option. 

Go to the Exchange section in the Office 365 admin center


8. In the Exchange admin center, click mail flow. 

Go to mail flow in the Exchange admin center


9. On the mail flow page, you’ll see a row of options. From the tab list, click rules. 

The Exchange admin center mail flow page


10. Click the Add (+) icon and select Create a new rule… 

Create a new rule to start your Office 365 signature


11. A separate lightbox window will open. Give your Office 365 email signature a name you will easily remember. 

Give your Office 365 signature a name


12. Click More options… at the bottom of the window. 

Click the More options link


13. In the *Apply this rule if… section, select how you want your signature to be applied.

For example, set your Office 365 email signature to only be included on messages to external recipients. 

Set conditions for your Office 365 email signature


14. Go to the *Do the following… section. Select Apply a disclaimer to the message… > append a disclaimer. This will add your signature to the end of an email.  

If you want it to appear before a message, choose prepend a disclaimer 

Select where the Office 365 signature should appear in a message


15. Now click on the Enter text… hyperlink. This opens the Office 365 disclaimer editor. Copy and paste your email signature design from your TXT file. Click OK. 

Enter the plain text or HTML code of your Office 365 email signature


16. You now need to specify a fallback action if the Office 365 signature cannot be automatically added to an email. There are three options to choose from: 

  • Wrap: A new message is created with the original one included as an attachment. Your Office 365 email signature is added to the new message and delivered to the recipients. This is the default option.  


  • Ignore: Your email is sent without the signature included. We recommend choosing this option. 


  • Reject: The email will not be sent. The sender will receive an NDR saying that the message could be delivered. 

17. Click OK > Save. Success, you’ve created an Office 365 email signature. 

How to add company wide email signatures in Office 365

By default, there is no central platform within Office 365 that can help you manage all users' email signatures. Each user has to manually set up their email signature via Outlook—an inefficient option if you have hundreds or thousands of users.

Given the limitations of manual setup and mail flow rules, using third-party tools offers many benefits. These tools can design, manage, and deploy professional Office 365 email signatures from one central location.

For instance, Exclaimer provides a robust system that lets you easily design professional email signatures that are automatically added to all Office 365 emails. It assures 'brand consistency' among all employees.

How to set an automatic Outlook 365 email signature

We can leverage Office 365’s mail flow rules to append text at the bottom of every email. This is a basic form of automatic signature addition but not as feature-rich as we might want it to be.

Steps to use mail flow rules for automatic signatures

  • Go to Microsoft 365 Admin Center -> Exchange -> Mail Flow

  • Click on ‘+’ symbol -> ‘Apply disclaimers…’

  • Fill out a name for your new rule in ‘Name…’ field.

  • Apply this rule if… -> [‘Sender is…’ trending_flat ‘OutsideInsideOrganization']

Choose all recipients inside your organization if you want this signature to appear on emails sent from within your organization only.

In ‘Add a disclaimer…’, copy-paste your plain text email template in 'Enter Text Field'.

Finish up by clicking on Save - now all emails sent from within your organization will have this disclaimer added as their email signature.

The limitations with a manual Office 365 signature setup 

Using transport rules and the Office 365 disclaimer function works if you’re just looking to ​add​ a basic signature. However, there are limitations to consider, beyond the manual work involved.  

For example: 

  • Outlook won’t automatically add signatures directly under each reply or the latest forwarded email. This causes signatures to ‘stack’ at the bottom of email chains. 

  • HTML email signatures on mobiles or Macs aren’t possible. iOS, as an example, tends to send emails in plain text, so HTML gets stripped out of emails altogether.  

  • Images can’t be inserted directly into an Office 365 email signature template. You must point to them on a public website using a hosted link. This means they may not appear in some email clients. Instead, images will show as red ‘X’ squares until recipients click ‘Download additional content’. 

  • You can’t test whether your Office 365 signature works correctly without enabling it and sending yourself a test email. This often needs to be done outside of core working hours. 

  • A new transport rule needs to be created for each departmental signature. In medium-to-enterprise organizations, this can become very complex and time-consuming. 

Choosing Exclaimer for Office 365 email signature management 

Designing and controlling email signatures in Office 365 is more challenging than first appears.  That’s why so many companies worldwide choose Exclaimer.  

With Exclaimer, you can create professional email signatures for Office 365 users with absolutely no IT expertise. From one central location, a non-IT user with no HTML skills can design and deploy multiple signatures with just a few clicks.  

The drag-and-drop signature designer lets you easily add different visual elements like logos, promotional banners, social media icons, and user photos. And any signature updates can be automated using simple, yet powerful rules. 

All contact details are automatically pulled from your Active Directory, plus you can include custom attributes where needed. Any fields that aren’t populated for a specific user will automatically be hidden without messing up your design.  

And this just scratches the surface of what Exclaimer can do. So, make the smart choice and get yourself a free trial of this cutting-edge Office 365 email signature software today.  

Take your email signatures for Office 365 to the next level

Exclaimer’s email signature manager for Office 365 boasts a variety of features designed to help your business soar to new heights.

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Frequently asked questions (FAQs) about creating Office 365 email signatures

Can I add an image to my Office 365 email signature?

Yes, you can add images, but they must be hosted online and referenced with a URL. Outlook does not support embedded images in signatures, meaning recipients might initially see a placeholder (red 'X') until they choose to download additional content.