my email exchange account is blacklisted and blocked for outgoing mail

Question

Email account is blacklisted and blocked for outgoing mail

Answer 1

Something here may help.
https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/use-the-delist-portal-to-remove-yourself-from-the-office-365-blocked-senders-lis?view=o365-worldwide

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Answer 2

Hi,
I agree with DSPatrick.
Is this issue with only one user?
Did you do anything before the issue occurred?
Please following the steps below and see if the issue is resolved.

1. In a web browser, go to https://sender.office.com.
2. Follow the instructions on the page. Ensure that you use the email address to which the error message was sent, and the IP address that is specified in the error message. You can only enter one email address and one IP address per visit.
3. Click Submit. The portal sends an email to the email address that you supply.
4. Click the confirmation link in the email sent to you by the delisting portal.
5. In the delist portal, click Delist IP.
   In addition, please make sure that there is no spam in your mailbox before you perform the above operations.