E-Mail sending to Offcie/Microsoft365 customers not possible - 451 4.7.500 Server busy

Koes 360 Reputation points
2023-10-11T10:38:11.0866667+00:00

Hi,

since this morning 5 am we are not able to send E-mails to office365/Microsoft365 Customers. Our Mails are stuck in our own queue and get the response: host customername.mail.protection.outlook.com 451 4.7.500 Server busy please try again later wit 193.228.149.133 S77719

Can someone check, why we are on an throtteling list with our E-MailServer and remove please?

Exchange Online
Exchange Online

A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates.


175 answers

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  1. Johnny Authement 0 Reputation points
    2023-10-11T14:54:26.7133333+00:00

    @outlook.com Please whitelist 69.2.42.130

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  2. Seidel, Johannes 0 Reputation points
    2023-10-11T14:52:24.1133333+00:00

    Hi,

    same issu here.

    Please whitelist the following ip´s:
    213.61.227.182
    213.61.227.189
    213.61.227.190

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  3. Alain D 21 Reputation points
    2023-10-11T14:51:36.8966667+00:00

    @outlook.com Please allow the following IP addresses :

    193.....

    145.....

    Thanks.

    Oct 11, 11pm : Mails are gone from Queue. Don't know if the antispam rule or ip whitelist that did the trick.

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  4. Abel Ruiz 0 Reputation points
    2023-10-11T14:51:20.8433333+00:00

    Same from Spain

    Please, whitelist 88.12.20.97

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    0 comments No comments

  5. Holger Muehlbauer UK Account 0 Reputation points
    2023-10-11T14:46:09.2666667+00:00

    Hi,

    please whitelist 213.206.174.144 and 213.206.174.145

    Regards

    Holger Mühlbauer

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