This method is not the recommended way to manage emails with multiple users on a single mailbox. Microsoft is gradually closing this loophole. For best results and long-term compatibility, use Shared Mailboxes as officially recommended.
However, if you still wish to proceed, follow the steps below to set up multiple signatures for one mailbox using the Outlook desktop client.
Choose the correct email account from the dropdown at the top.
Either:
Create a new signature by clicking "New", or
Edit an existing signature from the list under “Select signature to edit”.
Use the editor below to add text, images, or links to your signature.
Be cautious with the number of images, hyperlinks, or promotional text you include in a signature. Overuse of these elements increases your spam score, which can result in your emails being flagged or undelivered.
Final Note
As previously mentioned, this method exploits a workaround that Microsoft is gradually shutting down. If your organization needs multiple users to send emails from one mailbox with individualized signatures, a Shared Mailbox is the officially supported solution.
For advanced signature management, consider using a third-party solution like Exclaimer, which is available upon request.