Fehlermeldung: 550 You are not allowed to use the domain outlook.de as DATA From domain

Hallo Erik,
Welches Abo hast du bei Microsoft 365?
Kannst du eine Terminanfrage in OWA im Browser erstellen und bekommst du auch eine Fehlermeldung?
Mit freundlichen Grüssen
Galin Karlov
Microsoft 365 Support Engineer

Hallo Erik,
Bitte mache eine Office Online Reparatur und erstelle einen neuen Outlook Profil.
Mit freundlichen Grüssen
Galin Karlov
Microsoft 365 Support Engineer

Hallo Galin,
danke für Deine Nachricht. Ich nutze das Abo Microsoft 365 Business Standard.
Im Browser kann ich Terminanfragen stellen, in der Outlook App kommt aber die o.g. Fehlermeldung.
Viele Grüße
Erik

Hello Ben_07,

Welcome to Microsoft Community.

I am a Microsoft user just like you, I hope you are doing well?

Is the organiser trying to sign in using the same device as you? Is your account an underage account?

If the organizer is unable to sign in or reset their Microsoft account password, they should try account recovery form.

If your account is an underage account, only the account that added you to the Family group can remove you, therefore account access is required.

To try submitting Recovery Form, use link attached: https://account.live.com/acsr

After you submit the form, you will receive the results of your recovery request to the working email address you provided at the beginning of the form within 24 hours.

Your next steps depend on whether we could verify your account:

If it is "We could not verify your account", you will need to keep trying as many times as you want, up to two times per day.

If it is "We verified your account", Microsoft will use the same working email to send you instructions for how to sign back into your account.

Helpful tips

1 . Answer as many questions as possible. If you’re not sure, guessing is ok — wrong answers don’t count against you. When you get to a question that lets you “add more," fill in as much information as you are able.

2. Use the information you created when you created your account or when it was last updated.

3. Submit the information from a computer that you use regularly.

4. You will be asked to list the email addresses you have used recently and the subject lines of emails you have recently received. Ask family, friends, or business contacts for help in verifying their email addresses and for the subject lines of the last three emails they sent you.

5 Make sure you're using the correct domain for your account, such as hotmail.com, live.com or xbox360.com. Remember that your email address may be country specific. For example, if you created your account in Germany, your domain would probably be "hotmail.de" rather than "hotmail.com".

https://support.microsoft.com/article/b19c02d1-a782-dee6-93c3-dc8113b20c42

Please let me know if you need more assistance.

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Warm Regards

Have you tried clicking on the status that said password needed ? It should show you a window to login , once it does , since you are on AD, on the username box , instead of using your email address , use this format instead DOMAIN\Username

Example: Testnet\user1