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. Houssem 0 Reputation points
    2023-10-11T14:29:01.51+00:00

    Hi

    We are facing the same Errors in Tunisia

    @outlook.com , please allow these affected IPs to your whitelist:

    196.224.96.6

    196.224.96.4

    197.26.11.132

    197.26.11.133

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  2. Jorge Ramalho 0 Reputation points
    2023-10-11T14:29:50.2866667+00:00

    Hello,

    We have the same issue from Portugal.

    Please whitelist the following ip´s address 88.157.223.30 / 195.23.36.78.

    Thanks.

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  3. Michael Bietz 0 Reputation points
    2023-10-11T14:30:49.0833333+00:00

    Please whitelist following IPs

    89.245.134.142

    89.245.134.147

    89.245.134.151

    89.245.134.141

    Thank You

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  4. Matthias Baes 0 Reputation points
    2023-10-11T14:31:23.4333333+00:00

    Belgium affected: Please Whitelist:

    84.199.123.164

    84.199.123.174

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  5. Silva Joaquim 0 Reputation points
    2023-10-11T14:31:59.3166667+00:00

    Please whitelist the following ip

    148.196.30.44

    148.196.30.87

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