Digvijaysinh Zankat Supported triggers are listed here and there is no trigger specifically for Azure AD changes. Based on article https://blog.darrenjrobinson.com/subscribing-to-azure-ad-change-notifications-with-powershell/ you can set up Azure AD Change notifications and use NotificationURL to trigger Azure Functions via HttpTrigger.
I see you are interested only in email address update; however, I don't see it is supported as per doc: Supported resources but you can have changeType user
(user resource type). (Similar discussion)
I hope this helps with your question and let us know if you have any other.