Create a signature that applies to all messages –

To create a signature that applies to all messages, follow these steps:

1. Sign in to the Exchange admin center. Tip: You can also get to the Exchange admin center from the Microsoft 365 admin center. Sign in to the Microsoft 365 admin center and then from the left navigation bar, select … Show all. Under Admin Centers, select Exchange.
2. From the left navigation bar, select Mail Flow to expand it.
3. Under Mail Flow, select Rules.
4. In the Rules page, select + Add a rule, and then select Apply disclaimers.
5. In the Select rule conditions page in the New transport rule pane:
   1. In the Name field, enter a name for the rule.
   2. Select the Apply this rule drop-down menu and then select Apply to all messages.
   3. Select the following drop-down menus and select Apply a disclaimer to the message in the left menu and append a disclaimer in the right menu.
   4. Under the “Do the following” drop-down menu:
      1. Select the Enter text link. In the specified disclaimer text pane that opens, enter the text of your disclaimer, and then select Save.
      2. Select the Select One link. In the specified fallback option pane that opens, select Wrap, and then select Save. This option only applies if the disclaimer can’t be added because of encryption or other mail settings that block the signature. When Wrap is selected, the signature is wrapped in a message envelope.
   5. If desired, select the Except if drop-down menu, and then choose whether you want an exception for one of the listed items in the left menu and the condition in the right menu.
   6. Select Next.
6. In the Set rule settings page in the New transport rule pane:
   1. Under Rule mode, select Enforce to turn on the disclaimer immediately. To test the disclaimer first, select either Test with Policy Tips or Test without Policy Tips instead.
   2. Select a severity level in the Severity drop-down menu.
   3. Select Activate this rule on and specify a date to activate the rule.
   4. If desired, select “Deactivate this rule” and specify a date to deactivate the rule.
   5. If desired, select Stop processing more rules. Select this check box to avoid applying additional rules after this rule processes a message.
   6. If desired, select “Defer the message” if rule processing doesn’t complete. Select this check box to resubmit the message for processing. By default, the rule is ignored, and delivery of the message continues as normal.
   7. For the Match sender address in the message drop-down menu, leave it at the default of Header. This option isn’t relevant in this scenario since the rule applies to all messages.
   8. Select Next.
7. In the review and finish page in the new transport rule pane, review the settings for the new rule, and then select Finish.
8. When the rule finishes saving, select Done.

Limitations of organization-wide email signatures

The following limitations are limitations when managing email signatures in Microsoft 365:

• You can’t insert the signature directly under the latest email reply or forward.
• Users can’t see server-side email signatures in their Sent Items folders.
• You can’t embed images in email signatures.
• Rules skip lines that contain variables they can’t update. For example, if you use a variable for a user’s phone number but the phone number isn’t provided for a user, the system skips the line containing the variable.