Azure Communication Service - Additional From Addresses Greyed Out and Microsoft IP's Blacklisted

Question

I'm busy setting up a wordpress website using WP Forms for contact form submissions.

I decided to use Azure Communication Services as Azure is the cloud service provider I'm the most familiar with. Setup was fairly straightforward, and I managed to add my custom domain and verified SPF, DKIM and the domain itself.

Test emails sent from WP Forms configuration delivers without issues. However, as soon as I use the actual contact form, and use the submit button, the email arrives in the designated mailbox as spam. Here's where it gets interesting.

Using mxtoolbox's message header analyzer, two of the routes, both belonging to Microsoft are on a blacklist according to the analyzed header report. Furthermore, DMARC, SPF, and DKIM is successful, but DKIM authentication fails.

I am also trying to add another from email address in Azure Communication Services, but the Add+ button is greyed out. I tried logging a support call to Azure but to my surprise, it seems to have moved to a paid model since the last time I logged support requests.

How does Microsoft expect members of its community to make them aware of blacklisted IP's and email routes if they put support behind a payment gateway? Sigh.

Anyway - I would very much like to resolve this as I am starting my startup and the website is going live soon but if I cannot get successful email delivery with my contact form, then I'm going to have to remove that functionality from the website or try another bulk email service provider until this Azure Communcation Service is fleshed out more.

Thanks for any assistance.