Hi @Mike Gaum ,
I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to "Accept " the answer.
Issue:
You were sending a B2B invitation email but the domain display name was showing an incorrect prefix/field: [contoso.com]contoso.com instead of contoso.com
Solution:
Outlook was not parsing an aria-label correctly for the Domain field when the email was sent to an I @outlook.com address. The email showed up correctly when sent to a @gmail.com address.
To get around this issue, you are extracting the redemption URL and adding it to a personalized email.
Since I was not able to reproduce this issue in Outlook, please feel free to share feedback in the feedback forum for that team.
Please remember to "Accept Answer" if any answer/reply helped, so that others in the community facing similar issues can easily find the solution.