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. Anonymous
    2023-10-11T13:23:37.16+00:00

    In Poland we have the same problem

    Please add to Whitelist

    194.213.1.14

    194.213.1.29

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  2. kp 0 Reputation points
    2023-10-11T13:22:37.13+00:00

    we are suffering from this problem too.

    please whitelist:
    62.138.184.253

    Was this answer helpful?


  3. Jeroen Hermans 0 Reputation points
    2023-10-11T13:22:21.4066667+00:00

    Same problem in Germany

    Please add :
    81.201.118.37

    81.201.118.36

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  4. Michael Armstrong 0 Reputation points
    2023-10-11T13:22:10.5733333+00:00

    We're having the same issue in germany.

    Please Whitelist the ip

    188.64.59.57

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  5. Silvio Spagnoli 0 Reputation points
    2023-10-11T13:22:07.0866667+00:00

    same problem in Italy

    plz add to whitelist

    78.4.31.53

    212.28.160.0/25

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