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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
Hi @kai shien ,
Welcome to Q&A!
Before going further, may I know if this receiving outside emails issue only happen to specific users or happen to all the users in your organization?
Based on the test results you provided, looks like your issue is more related to your MX records and server ports. So, in order to further confirm your issue, it is suggested for you to check if your MX record has been properly configured to point to the public IP address of the Exchange server. If all those settings has been configured properly, as I know, DNS cache might cause similar issues as yours. Please try to re-fresh your DNS cache and re-try the Microsoft Remote Connectivity Analyzer tool to see if your issue would has any difference.
Any updates, please feel free to post back.
Hi @kai shien ,
Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.
Hi Jeff, sorry for the delay.
As I understand the MX record should be correctly configured, as before I move it, I export the records out and import back exactly, then double confirm if the MX record is well inserted and same as original. We havent change anything on the mail server (At least from my side)
Do you need me to send you the original full DNS record txt from my domain?
mail1 1800 IN A 14.xxx.xxx.xxx
mail2 1800 IN A 14.xxx.xxx.xxx
; MX Record
@ 3600 IN MX 10 mail1.xxx.com.
@ 3600 IN MX 20 mail2.xxx.com.
Hope to hear from you thanks
Hi @kai shien ,
Thanks for your reply.
Since you just imported them back, that might no longer be the key point of your issue.
cannot receive email from outside (such as Gmail, yahoo), but can send out email only
Did those sender receive any NDR emails after send email messages out?
In order to further confirm if those email messages has arrived to your mail server, it is suggested for you to check the message tracking log and see if there is any records about those "not-received" email messages.
By the way, just in case, please check if you have enabled any spam filters which might blocked those emails.
Yes. I did receive the NDR email that bounced back saying
From yahoo
Sorry, we were unable to deliver your message to the following address.
<test@X .com>:
550: The specified recipient is not accepted (using messageid: b293fffa-e442-11eb-bc38-00900b3ec5a2)
From Gmail
Error Icon
Address not found
Your message wasn't delivered to test@X .com because the address couldn't be found, or is unable to receive mail.
The response from the remote server was:
550 The specified recipient is not accepted (using messageid: 32d1e75c-e2f6-11eb-9986-00900b3ec5a2)
Hi @kai shien ,
Thanks for your information again.
Seems that you did not post the full NDR messages, would you mind helping check the generating server of these NDR email messages? If the generating server is not your Exchange server, I'm afraid that those email messages had never arrived to your Exchange server, which would still point to your MX record configuration.
By the way, I noticed that you are always using the same user mailbox for test, in order to avoid possible factors, would you mind creating a new user mailbox to do the same test operation and see if the issue has any difference.
Hi, the email address all under the same domain is having the same issue, so the test mailbox is good enough for this test. If the test mailbox can receive, mean the rest of the mailbox can receive already.
Do you want me to attach the 2 full raw message for you here?