Can we fix (so we can predict) the originating telephone number for MS authentication calls?
For our small office, I want to configure Office 365 MFA's secondary validation method as being a call into our office number. (I know we can use the authenticator app but, for one particular account, that isn't the best solution for us). However, we have an auto-receptionist on our VOIP system with the result that authentication calls from MS time-out whilst in the queue.
I can create a rule on our VOIP system which will allow MS authentication calls to by-pass the auto-receptionist: inbound authe tication calls would be directed to a particular handset and, from MS' perspective, the call would only be "answered" when someone pickes up that handset (i.e. the auto-receptionsit would not intervene).
My issue is that we need to specify the originating caller ID/phone number in the rule. Our tests have shown that calls from MS originate from a range of numbers.
Hence, my question: is there a way to fix the originating number MS will use, so that I can configure my VOIP rule?