Exchange Server cannot receive email anymore

kai shien 1 Reputation point
2021-07-15T02:37:41.107+00:00

Hi, recently I had moved the dns host from Godaddy to Aliyun, but then the email hosted under IIS no longer working,cannot receive email from outside (such as Gmail, yahoo), but can send out email only.

So I decided to mvoe back to DNS back to godaddy, but it will not work anymore.

I have no idea what causing it as we never change anything on the email server.

Take note the web server and email server is separated.

I tried to do the testing from https://testconnectivity.microsoft.com/ for Inbound SMTP and POP3, both also failed.

This is the test result for Inbound SMTP: https://testconnectivity.microsoft.com/result/a6d55e3d-1750-e6b6-1f29-bb92b0545985

Attempting to send a test email message to test@xxxxxxxxxxxxx .com using MX mail1.xxxx.com.Delivery of the test email message failed.

Additional Details
The server returned status code 550 - Mailbox unavailable. The server response was: The specified recipient is not accepted (using messageid: 3d9eeb2c-e453-11eb-9986-00900b3ec5a2) Exception details: Message: Mailbox unavailable. The server response was: The specified recipient is not accepted (using messageid: 3d9eeb2c-e453-11eb-9986-00900b3ec5a2) Type: System.Net.Mail.SmtpFailedRecipientException Stack trace: at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception) at System.Net.Mail.SmtpClient.Send(MailMessage message) at Microsoft.M365.RCA.ConnectivityTests.SmtpMessageTest.PerformTestReally()

POP3 result
Port 995 and 110 also failed

Testing POP for user icon\test222 on host mail1.xxx.com:995:SSL.The POP test failed.
Attempting to resolve the host name mail1.xxx.com in DNS.The host name resolved successfully.

Additional Details
IP addresses returned: 14.xxx.xxx.xxx
Testing TCP port 995 on host mail1.xxx.com to ensure it's listening and open.The specified port is either blocked, not listening, or not producing the expected response.

May I know what happen or what Can I do to make it work again? I can provide you the DNS details if you need it.

Thanks

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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