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.


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  1. Didier BIBAL 10 Reputation points
    2023-10-11T13:21:50.6133333+00:00

    Hi. Whitelist for 185.29.40.20 please. Thanks

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  2. kc 0 Reputation points
    2023-10-11T13:21:39.5066667+00:00

    please Whitelist our IPs :

    103.230.125.210

    103.230.125.211

    103.230.125.212

    103.230.125.215

    103.230.125.216

    103.230.125.217

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  3. Gençosman Öztürk 0 Reputation points
    2023-10-11T13:18:09.1333333+00:00

    same problem in Türkiye

    plz add to whitelist

    193.36.184.213

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  4. Casey Witham 0 Reputation points
    2023-10-11T13:16:59.3433333+00:00

    Comment removed.

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  5. Anonymous
    2023-10-11T13:16:57.6933333+00:00

    Pleas add to whitelist :

    mail.ugr.be
    noumayos.ugr.be
    relay3.ug.be

    178.248.160.120

    178.248.160.121

    185.175.180.2

    Thanks !

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