Email communication within and outside an office acts as the lifeline of an organization. Any flaw in sending or receiving emails through Exchange Server can pose a severe threat to its functioning. Interaction with clients becomes a big issue, posing a major setback to business continuity.
One such error is “Exchange Server Not Receiving External Emails”. This in itself is a big trouble and can drive your clients away due to a non-working communication channel. Several reasons can be responsible for this glitch, and there can be various methods to troubleshoot it.
Right here, we will discuss different methods to fix the error. Additionally, we also explore a professional exchange recovery tool, such as Stellar Repair for Exchange, to remedy this situation.
What Do You Mean By External Emails?
The external emails refer to the emails sent from domains other than those of your organization. For instance, emails sent via Gmail, Hotmail, Yahoo, or any other organization’s business email. The error signifies that the emails from customers and other business stakeholders outside your company’s network go undelivered. Something is stopping them from entering your inbox. There can be many reasons for this failure to receive external emails. These may include issues or complications in the configuration settings, DNS, firewall settings, mail flow, or in the Exchange server itself.
Methods to Fix the Error
If you are also coming across the “Exchange Server Not Receiving External Emails” error, the manual methods given here can fix the issue.
1. Verify MX Records and DNS Configuration
The foremost way to troubleshoot this error is to ensure correct DNS configuration, specifically, the MX records. These records provide information about the mail servers that receive email for your domain.
MX Records: To check the MX records, you can try an online DNS lookup tool. Alternatively, the below PowerShell command can also help:
nslookup -type=mx yourdomain.comCheck if the records indicate the correct IP address for the Exchange Server. In case of an incorrect or missing IP address, update it manually so the public IP of your server becomes visible.
DNS Resolution: Next, verify the role of DNS in providing external domain names correctly by using the nslookup google.com command.
Failure of this command will suggest the need for adjustment of your DNS configuration.
2. Check Firewall and Port Settings
Simple Mail Transfer Protocol (SMTP) uses Port 25 for sending and receiving emails. During email communication, firewalls can block several ports for security reasons, and Port 25 is one of them. You need to check if it is open on:
- Your Exchange server
- The firewall between the server and the Internet
To verify this, connect the server via telnet through this command: telnet smtp.yourdomain.com
A failed connection will indicate halted traffic on Port 25. Adjusting firewall rules will help to resume the traffic. In addition, also check if Port 443 (HTTPS) or Port 587 (submission) is open.
3. Mail Flow Configuration
For a flawless mail flow, Exchange Server settings, such as Send Connectors and Receive Connectors, should have a correct configuration.
To verify the perfect working of the Send Connector, do the following steps:
- Create a message and send it to an outside recipient from an internal mailbox.
- Verify if the recipient has received the message.
- If the email fails to deliver, check Queue Viewer
- If you are not receiving external emails, check Transport Logs and use the cmdlet Get-MessageTrackingLog with -EventId RECEIVE option for tracking emails. For example:
Get-MessageTrackingLog -EventId RECEIVE -Recipients “[email protected]”
- Also, check the Send connector configuration and set it to Usage: Internet and set Address Space = *, which refers to all external domains.
Similarly, check the working of the Receive Connector. Here are the requisite steps:
- Open Exchange Management Console (EMC).
- Click Mail Flow > Receive Connectors.
- Check the configuration of the Receive Connector
- Make sure it accepts inbound SMTP traffic from external domains.
4. Check Transport Rules
Scan through the transport rules to find out if any of them are stopping external emails from entering the server. At times, email transport rules can reject or redirect some specific emails that fulfill the blocking criteria. Here is how you can check the transport rules:
- Open Exchange Admin Center (EAC)
- Navigate to Mail Flow > Rules
- Go through the rules to find out if there are any restrictive rules
- Disable the rule that is restricting the entry of emails on the server
Here is the default syntax to disable a particular transport rule.
Disable-TransportRule
[-Identity] <RuleIdParameter>
[-Confirm]
[-DomainController <Fqdn>]
[-WhatIf]
[<CommonParameters>]For example, the command below will disable the Sales Disclaimer rule.
Disable-TransportRule -Identity “Sales Disclaimer”
5. Use Telnet to Check Email Flow
Admins use Telnet, a networking protocol, to connect to a remote computer through a text-based connection over a TCP/IP network. It helps to check email flow in Exchange Servers. You can use it by creating a direct, plain-text connection to SMTP Port 25 to check if it is receiving emails from external servers.
6. Scan through Anti-spam configuration
Often, anti-spam filtering can block external emails from entering your Exchange Server. You can check it by reviewing Blocked Senders in the Exchange admin console. If you find genuine external emails, unblock them. Additionally, navigate to Protection > Spam Filter and temporarily disable the anti-spam features in the Exchange Admin Center. It can also resolve the error.
Use Stellar Repair for Exchange to resolve the Error.
At times, a damaged, corrupt, or dismounted database can lead to the “Exchange server not receiving external emails” error. In any such instance, a professional exchange recovery tool such as Stellar Repair for Exchange can help. The software can repair and recover the mailbox items of a corrupt database. This will restore mailbox access and re-enable the perpetual mail flow.
In addition, the professional exchange recovery tool can perform several other crucial tasks for flawless working of the Exchange Server Databases. Here are some of its crucial features:
- Repair the corrupt EDB file and restore all mailboxes
- Processes up to 8 mailboxes simultaneously with parallel processing technique
- Recovers deleted Exchange mailboxes
- Perform granular recovery based on various filters and search criteria
- Enhanced preview of mailboxes and mail items
Conclusion
Your business can suffer a major setback in the absence of emails from your clients. This is quite a possibility if your Exchange Server shows the “Exchange Server Not Receiving External Emails” error. This can happen because of complicated configuration settings, DNS issues, firewalls between the internet and the Exchange Server, mail flow errors, and issues in the Exchange Server itself.
You may try several methods to troubleshoot this problem. For example, you can verify MX records and DNS configuration, check firewall and port settings for modification, change mail flow configuration settings, or test transport rules. Other methods include using Telnet to check email flow or looking at anti-spam configuration if it needs changes.
In many instances, the problem may occur due to a dismounted, damaged, or corrupt database. To troubleshoot the error in any such situation, it is better to use a professional exchange recovery tool such as Stellar Repair for Exchange.
The software allows you to recover and restore the Exchange databases and the contained mailboxes easily, allowing uninterrupted email communication.