Hi ghawton,
I did some testing and I am able to replicate this behaviour. Unfortunately, I don’t see any actions on the screen itself for performing email address validation on save. Due to this, I’ve created a ticket for our development team to investigate. For the time being, the only work-around that I can provide you is the following:
1) Copy and remove (or cut) the additional emails from the customer
2) Save the customer record along with the necessary changes in Method
3) Open the customer in QBO and paste back the email address data
I’ll keep you posted on any updates that I receive via this thread.
Sorry for the inconvenience.
Audisho