Office 365 / Postfix - multiple Tenants

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Hi all

 

I'm a bit stumped on this one so hoping someone can help.

 

I have 2 schools with separate Office 365 tenants, I'm currently hosting something for the 2nd school in the first and want to route mail through their tenant for that and thought about using my existing Postfix relay.

 

I'm a little stumped as to whether or how I can setup Postfix so that it will route mail through different tenants based off the sender.

 

Anyone able to help/advise?

 

Thanks