Hi @Alexandru Ioja
Great to know that the issue has already been resolved and thanks for sharing the 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 to help more users who encounter the same problem.
Case title: How to remove device from Company Portal not having access to that email?
Issue Symptom: I just moved from one company to another and I need to sign in my Teams on my mobile but I can`t access it because I didn't un-enroll my device from the Company Portal but I don't have the email address anymore because it was deleted.
Resolution: Going into settings -> searching device management -> VPN & Device Management ->remove the old management from there
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