Fixed: Exchange 2013 Stops/Not Receiving External Emails

Exchange Administrators are frequently posting the same issue on MS Exchange 2013 forum...They aren’t receiving any external any email in Exchange Server after installed the current server!

I was also stunned when the very first time I saw that issue on a forum where number of users was searching for the solution to fix that issue. So after examined few very similar cases on our Exchange environment, I finally got the solution to fix email not receiving issue in Exchange 2013. So in this blog post I will show you the best ways to fix that issue. Just follow the steps-

As you have configured Exchange Server 2013 by followed all the guidelines recommended by Microsoft including Firewall, MX records, Send & Receive Connectors and few others but getting no positive result, probably the key reason could be incorrect SMTP external settings. So before moving to the solution, let’s see how to fix if you’re also not receiving any internal email too. 

Fix Internal Email Receiving Issue

Before apply the solution, confirm that your DNS IP (local domain) is set on NIC of Exchange server and nslookup is working perfectly and resolving. But there is another mishap-

1. Remove secondary DNS IP and restart Exchange Server transport and frontend transport service if you have setup secondary DNS IP address in NIC (Network Interface Card) of Exchange Server.

2. Once you have done as mentioned in first step, now configure local DNS IP on Exchange DNS lookups.

To create a new DNS server IP, open and login in Exchange Control Panel (ECP) and click to open Servers section.

Select Exchange Server and click Edit, then select DNS Lookups.  

Select Custom settings option under Internal DNS lookups and enter your local DNS IP. By configuring this manual setting, internal email slow start working in mostly cases.

 

Now I move to the main topic and suggest you the similar solution as we have done in internal email flow issue.

How to fix External 2013 stop receiving external emails issue

Initially, open Microsoft Remove ConnectivityAnalyzer and check server’s incoming email status by clicking on Inbound SMTP Tests option under Internet Email Tests. As it has been noticed few problem in inbound external emails on newly installed Exchange Server 2013, so it is recommended to check SMTP status on Remote Analyzer tool. As your server has external email receiving issue, so it will show an error at last. 

Now check the transport logs to get the reason why incoming emails are rejecting by the server. Check transport logs by navigating through – 

 (C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\Logs\FrontEnd\ProtocolLog\SmtpReceive)

Now do the same as we did above to fix internal email not receiving issue. But this time enter the local DNS server IP under External DNS lookups. Once you have done, restart Exchange Server transport and frontend transport service.

Now check it again, hope this time you will get all important pending emails. But in case if this solution doesn’t work, try this-

Open host file of Exchange Server 2013 and insert the entries-

10.10.10.100         mailserver

10.10.10.100         mailserver.yourdomain.com

Now restart Exchange services once you have modified host file. This solution also works in many other cases where user complains about not getting outside emails.

However if the same issue still persists, recheck transport log file, Remote Analyzer, and Firewall logs to get the idea to fix this issue.