Free/busy sharing Exchange Hybrid and Exchange Online

[PMorgan_1116]

Hoping someone can clarify...

I'm trying to figure out exactly how to go about setting up free/busy sharing between two organizations where one is Exchange 2019 hybrid and the other is strictly Exchange Online.  So, here's the scenario...

Company A (hybrid) wants to share free/busy data with Company B (Exchange Online) - and not the other way around (no sharing from Company B back to A).  So...if I'm thinking through it correctly, I need to create an Organizational Relationship in Company A, but what needs to be done in company B?  Does an organization relationship need to be created there also?

And, how would this change if both companies wanted to share with each other?  I'm thinking an org relationship would need to be created in both Company A and B, correct?

Thank you for any assistance.

[#2]

Org relationships are one-way only, so if it's a one-way sharing you need, that should do it. When/if you want to switch to two-way, create an org relationship in the other organization as well.

[#3]

@Vasil Michev Thank you for the reply.  So, just to make sure I have it correct, I don't need to create anything at all in Company B (assuming they don't want to share with anyone).  From what I've read I keep thinking a federated trust needs to be created on that end and an org relationship on the side of sharing, but from your response it doesn't look that way, correct?

[#4]

As detailed in the documentation: https://docs.microsoft.com/en-us/exchange/sharing/organization-relationships/organization-relationsh...

When you set up the organization relationship, you are setting up your side of the relationship and specifying the level of information that the users in the external organization can view. The external organization may set up the same or different settings on their side. For example, if Contoso creates an organization relationship with Tailspin Toys, the users at Tailspin Toys will be able to schedule meetings with the users at Contoso by adding their email address to the meeting invitation. The availability of the invited Contoso user would display to the Tailspin Toys user. However, before Contoso can also see availability for users at Tailspin Toys, their administrator needs to set up an organization relationship with Contoso.

---