Pending/confirmation email not arriving to outlook email addresses

Hi, I have set the system up, but just noticed that my personal hotmail.co.uk email does not receive any messages from the bookings plugin. (I used this to test with me being the customer using hotmail address).

I tried installing Post SMTP to see if that helped, but no emails at all arrive in hotmail account. I can use my gmail address with no issue, but some customers may use outlook, and need to see the emails for confirming the appointment.

Any ideas how to make this work?

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