Tag not monitored by Microsoft.
MC IDs have not been used since the merger of Certification profiles and Learn profiles in 2024. Your Learn username is now your unique ID.
https://learn.microsoft.com/training/support/faq?pivots=profile&source=docs#what-happened-to-my-mcid
Due to privacy and security policies, if you have lost access to the email account it is not possible to access your certifications plus it is not possible to transfer certifications between Learn profiles.