Some emails are not received from external domains

Have you test with MS remote connectivity analyzer.  What is the out come.  

https://testconnectivity.microsoft.com/

Hi Steven,

Given the lack of NDRs, what was it that alerted you to this?  I am thinking that you may be able to use that catalyst to track what is happening, back to the source of the issue.

Do your firewall logs show incoming connections from the correspondent?

What do your Message Tracking Logs show?

Use this form of PowerShell command (Exchange Management Shell) to get those:

Get-MessageTrackingLog -Resultsize "Unlimited" -Start "10/28/2017 09:46:01" -End "10/28/2017 09:48:59" -Sender "username1@example.com" -Recipient "username2@example.com" | Export-CSV C:\Temp\ZZ_MessageTrackingLog.csv -NoTypeInformation

Select allOpen in new window

Change the start and end dates / times to narrow it down (reduce the data to check.  You can omit the sender or recipient if you aren't sure, and change the C:\Temp\ to whatever suits.

Open the file in Excel (say).

Thanks,

Alan.

Hi,


The strange thing comes that if the recipient is a new user,it works. He received the email but migrated users do not receive email from some external domains.


@Pushpakumara Mahagamage: Which test do I need to perform?

@ Alan: I noticed because some external users told us. Message Tracking shows no results. It is not arriving to Exchange but if i created a new user, he receives the email.

Cheers

Thanks for all the response. It was blocked in the smarthost