All too true.

Hi Tony,
I see what you mean. Though, if you look at little bit below where you quoted, in the table, it says:
“Default value: None”
So their documentation seems to contradict itself.
I personally found the setting on mine to be “None” by default.
It might be one of those things they changed recently and haven’t completely updated their documentation to reflect the change.

According to the documentation

All: Automatic Replies are sent to all external senders. This is the default value.

I don’t see that the default value is None, meaning don’t send any external replies. But it doesn’t do any harm to be specific.

I did a little more reading and found this syntax article: https://learn.microsoft.com/en-us/powershell/module/exchange/set-mailboxautoreplyconfiguration?redirectedfrom=MSDN&view=exchange-ps#-externalaudience

Which indicates the default is to not reply to anyone outside of the organization. Changing that parameter to “All” allowed things to work as expected.

Thanks. We do our best to publish practical, usable material on P365.

Check out https://docs.microsoft.com/en-us/graph/api/resources/automaticrepliessetting?view=graph-rest-1.0

I haven’t used this API, but it looks like the right one.

Yes.