An administrator may encounter with the most common problem while installing and configuring the Exchange Server i.e. ‘Exchange is not receiving external emails’. For instance, in this case, users are capable to send or receive all the emails on the local machine without any difficulty, whereas Exchange 2010 server can not receive mail from an external email address and create such type of issues when they have received an email by the server. In the upcoming section, we are going to explain the possible causes behind this error along with resolutions in a proper way.

Reasons For Errors Occurrence

There are following reasons due to which users may get an error while receiving the external emails in Exchange mailbox:

1. Improper shutdown of Exchange Server

2. Different hardware and software failures

3. Forced to Reboot and Restart system

Therefore, there is a need for such solutions, which helps to resolve this error.

Measures to Fix "Exchange 2010 Not Receiving External Emails"

In order to resolve this issue, first step that is followed by all administrators to verify that these problems may occur with emails that may be received. In case, if users are also facing the same problem, then, need to check it by sending one test mail from any random external emails to the internal email address. After this, go to the Exchange Management Console ( EMC ) and then, select Toolbox from the menu, and clicking twice on Message Tracking option. Now, users will be able to visible the new window, which will prompt for Login page. After finishing this login process next, follow the below-mentioned steps:

Step 1: Search for those messages that you may have received

Step 2: Now, Choose the user

Step 3: After this, type the email address from where the test messages generated

Step 4: Then, Click OK button

After giving the search results, now to get each detail by clicking double on the test message. In any case, the delivery report displays the failed message let's follow the next step. Failed mail report will be shown in below screenshot:

Next, go to the Start menu and select services.msc and then, click Enter button 




When users will able to appear the Services window, now start looking for MS Exchange Transport, and then click right on this option and choose the restart option



Once to restart the service then, repeat the external mail test process again and this time it would be fine.


Fix Error 'Exchange 2013 Not Receiving Some External Emails'

For an instance, users are using Exchange 2013 server and the same issue occurs whenever receiving an email. In such scenario when users send any emails for testing, then, the Microsoft remote connectivity software will show some errors in incoming SMTP mails. In such way to verify the issue users have to check the status of server’s incoming SMTP emails by using Microsoft’s remote connectivity analyzer. At last, it will display an error while receiving external email on Exchange 2010/2013/2016 as well. To follow below points to troubleshoot this error: 

  • First of all, configure the local DNS server within the external DNS lookups.

  • In servers settings, users can find it easily and put the DNS server IP locally for external DNS lookups.

  • After that, restart the Microsoft Exchange transport as well as Front end transport service

  • Apart from this, users can modify a Host file, this may help to fix this issue. For this, open the host file of Exchange 2013 and enter the host entries. Some modification in the host file may resolve this problem and the Exchange external transport service has restarted 

In any case, the above solutions do not work properly and still, users are facing the same issue, then need to check (MSRCA) Microsoft remote connectivity analyzer, Firewall logs, transport logs, and Exchange server event viewer. It will provide the users few hint to resolve this 'Exchange 2013 not receiving external emails' issue. Otherwise, one can take help of third party utility named as Exchange Email Recovery Tool to solve the exchange external email transportation issue in Exchange 2010/2013/ 2016 versions.

Conclusion

How to fix "Exchange 2010/2013/2016 is not receiving external emails" is still a big trouble for many users, if they may encounter this type of error. In such case, we have to various reasons due to which this error will occur and also mentioned the suitable solution to resolve the Exchange external emails problem. Also, we have suggested to clients that they should go for Exchange Email Recovery Tool if you encounter corrupt database issue on Exchange Server.