KnowledgeBase Articles » How do I set up SMTP Recipient Verification with Microsoft Exchange 2013/2016?

Friday, December 07, 2018, 15:44

How do I set up SMTP Recipient Verification with Microsoft Exchange 2013/2016?

Category: General

Solution ID: 00000310

Summary:

How do I enable SMTP Recipient Filtering with my Microsoft Exchange 2013/2016 server to perform recipient verification/validation/filtering?

Answer:

Following are the steps to enable recipient verification (recipient filtering) to allow PerfectMail to validate e-mail users for Microsoft Exchange 2013 and later.

Recipient filtering/Recipient verification is the process where inbound messages, from the Internet are verified as being valid on your Exchange server. If this feature is turned off "all e-mail addresses will be accepted" by both Exchange and PerfectMail.

Starting with Exchange 2013, the Exchange FrontEnd Transport service, by default, no longer rejects invalid recipients during the SMTP conversation. For recipient verification to function, the following needs to be done.

Please ensure you have the appropriate permissions to perform this task.

1. Ensure the Exchange Anti-Spam Agents are installed. You can check via Exchange Management shell with the following EMS command:
   Get-TransportAgent
2. Make sure that Recipient Filter Agent is listed and enabled. If it is not, install it with the following command:
   & $env:ExchangeInstallPath\Scripts\Install-AntiSpamAgents.ps1
3. Ensure that the Recipient Filter Agent is enabled. Use the following command:
   Enable-TransportAgent "Recipient Filter Agent"
4. Enable AddressBook. All of your domains need to be using Address Book to check for recipients. To check, run the following command:
   Get-AcceptedDomain | Format-List Name,AddressBookEnabled
5. If Address Book is disabled for any domains for which the Exchange server is authoritative, fix that with the following command, once for each such domain:
   Set-AcceptedDomain name_of_domain -AddressBookEnabled $true
6. At this point, restart the Microsoft Exchange Transport service.
7. Ensure that Recipient Validation is enabled. Run the following command:
   Set-RecipientFilterConfig -RecipientValidationEnabled $true
8. Again, restart the transport service.
9. Allow access to the Default receive connector. In the Exchange Administrative Center, go to Mail Flow : Receive Connectors.
10. Edit the default connector, go to the Security tab and ensure that anonymous users are allowed. This lets PerfectMail use the connector for recipient verification.
11. Test that Recipient Filtering works. On the PerfectMail console, go to Tools > SMTP Test. Set the "Server IP" to the IP address of your Exchange server, leave the "From" address blank and put a bogus email address in the "To" field. The Subject and Message fields can be blank. Click "Send". The server responses should be similar to the following:
    [+] Connected to 192.168.1.1 << myexchange.mydomain.com Microsoft ESMTP MAIL Service ready at... >> HELO perfectmail.mydomain.com << 250 myexchange.mydomain.com Hello ... >> MAIL FROM: <> << 250 2.1.0 <>... Sender ok >> RCPT TO: <bogus_user_123@mydomain.com> << 550 5.1.1 <bogus_user_123@mydomain.com>... User unknown >> QUIT [-] Closed connection

Tags: microsoft, exchange, 2013, smtp recipient, filtering, verification, validation, smtp

Link to this article: https://perfectmail.com/kb/exchange_2013_recipient_filtering

Updated: Friday, December 07, 2018, 15:44

-- David Rutherford