E-Mail sending to Microsoft customers not possible - 451 4.7.500 Server busy

Question

E-Mail sending to Microsoft customers not possible - 451 4.7.500 Server busy

Alberto Mendoza Lorenzo 0

We changed Internet providers, so with the new IPs we cannot deliver email to Microsoft domains.

Our domain is gcollado.com and the IP's are 189.240.121.19, 189.240.121.20 and 189.240.121.21.

Can you support us with this incident?

Thank you

Ana M Gauna 🇧🇷 1 Reputation point

2024-08-15T03:42:54.06+00:00

in the Windows Control Panel, in Network Device, in TCP-IP4 in the advanced item, in DNS enter these 3 IP numbers, record the information, restart the computer, and test if the email worked.
Anonymous

2024-08-29T02:19:09.2833333+00:00

Hi @Alberto Mendoza Lorenzo ,

Just checking in to see if above information was helpful. If the issue has been resolved, please mark the helpful replies as answers. Accepting an answer helps other community members to know the answer helped you. It is also a way to thank and recognize the person who helped you.

1 answer

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Ana M Gauna 🇧🇷 1 Reputation point

2024-08-15T03:42:54.06+00:00

in the Windows Control Panel, in Network Device, in TCP-IP4 in the advanced item, in DNS enter these 3 IP numbers, record the information, restart the computer, and test if the email worked.
Anonymous

2024-08-29T02:19:09.2833333+00:00

Hi @Alberto Mendoza Lorenzo ,

Just checking in to see if above information was helpful. If the issue has been resolved, please mark the helpful replies as answers. Accepting an answer helps other community members to know the answer helped you. It is also a way to thank and recognize the person who helped you.

Answer 1

Anonymous

Hi @Alberto Mendoza Lorenzo ,

Welcome to the Microsoft Q&A platform!

When you're unable to deliver email to Microsoft domains (like Outlook, Hotmail, etc.), it often involves issues related to spam filtering, IP reputation, or proper email authentication. Here are some steps you can follow:

New IP addresses often don’t have an established reputation, which can cause delivery issues. You can check the reputation of your IPs using tools like Microsoft’s delist portal to ensure they are not blacklisted.
Ensure that your domain’s SPF, DKIM, and DMARC records are correctly configured. These records help verify that your domain is authorized to send emails, improving deliverability.
Verify that your DNS settings, including MX records, are correctly set up for your new IP addresses. Incorrect DNS settings can lead to email delivery issues.
Since your IPs are new, it might take some time to build a good sending reputation. Sending consistent, non-spammy emails can help improve your IP reputation over time.

Please feel free to contact me if you have any queries.

Best,

Jake Zhang

Anonymous

2024-08-19T05:35:11.7166667+00:00

Hi @Alberto Mendoza Lorenzo,

Please kindly consider this comment as a warm follow up, I want to know if your problem has been solved. If you still have any other questions, please feel free to comment here and I'm glad to provide further support.If the above info is helpful to this question, you can click "Accept Answer". Have a nice day!

Best,

Jake Zhang
Anonymous

2024-08-21T07:03:11.7133333+00:00

Hi @Alberto Mendoza Lorenzo,

If the answer has been helpful, please consider accepting the answer to help increase visibility of this question for other members of the Microsoft Q&A community. If not, please let us know what is still needed in the comments so the question can be answered. Thank you for helping to improve Microsoft Q&A!

Best,

Jake Zhang

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E-Mail sending to Microsoft customers not possible - 451 4.7.500 Server busy

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