Are you receiving emails from third parties at your student address?
Did you apply for jobs or ministry positions using your student address?
Are you using your student email address as the username for Spotify, Apple, DoorDash or some other third party website?
Do you use “Sign in with Microsoft” to sign into any third party services using your student account?
If you answered “yes” to any of those questions, you may want to update your details with all of those parties.
Check through your inbox or archive for all emails received in the past 30-90 days.
Any you want to keep receiving, you’ll need to update your address with that person or company:
For subscriptions, there may be a “Manage Preferences” link at the bottom of the email
For other senders, reply to the sender to let them know where you can be contacted in future. CC your new address to make it easier for them to reply to you there
Email the hirer to let them know your email address has changed.
If you were to embarrassed to give them the personal address you registered as a teenager (hello_kitty123 or mega-awesome-dude68), it might be time to create a more boring professional personal email address that can follow you around in the future 
The steps will vary from vendor to vendor but most will allow you to login and update your email address.
Choose a long-lasting address such as a personal Gmail address so you don’t need to do this again every time you change role or academic institution.
You can see which services you have logged into with your Microsoft account by going to https://mysignins.microsoft.com and scanning through the list of sign-ins for third-party applications
If you see any you want to keep using, sign into that service and update your login method to allow you to sign in with a personal email address and password, rather than your M365 account