I'm sorry if this has been asked many times before. Feel free to call me a noob and tell me to do a search. (although I have done some searching and didn't find my exact situation.)
We have e-mail coming into our Exchange server addressed to multiple domains. There is no distinction. So, email@domain1.com also can receive e-mail on email@domain2.com. It doesn't matter.
How is this handled in Hybrid mode and ultimately Exchange Online. Do I have to add and verify every domain within Office 365 or does it just accept the mail from any domain that is sent to us?
What do I need to do to handle all these domains?