Hi @Glenn Maxwell ,
Do you mean to make a shared mailbox only receive or reject calendar invitation messages? If I understand the error, please correct me.
If this is the case, you could set up mail flow rules:
- In EAC, navigate to Mail Flow > Rules, click + to create a new rule.
- In the New rule page that opens, click More options.
- Apply this rule if > The recipient > is this person, select shared mailbox.
- Do the following, select Reject Message.
- except if > message properties > contains the message type, select calendar.
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