Hi @TimVavra , just so I make sure I understand properly, you are trying to add the users present in your B2C tenant as guest users into your actual AAD tenant? Now in order to this, you are trying to send an email with the invitation link so that the user can redeem that link and add themselves as B2C/Guest users to your actual AAD tenant. Now the problem you face is that, when you send the email to an email address fetched from B2C tenant for that user the email never reaches the user. Now based on this what I would like to know is if the email address mentioned by customer "tim.vavra@azurestageenvironment.onmicrosoft.com" is added in the email attribute of the user or not. It is added as value for the email attribute for the user in B2C, then make sure it has a valid mailbox attached to it. The email can only be sent if there is a valid mailbox available and attached to that emailID. If the email is a valid one, then both B2C and AAD, would be able to sent an invitation link on to that email and that the user can redeem easily.
What type of email does this user have when he tried to sign up in B2C tenant? We need more details around the user's email ID that was used to signup and if that email address is listed as a value for the email attribute of the user or not, and if that is a valid email id.
Please let me know and I can continue looking into this.
Thank you,
James