Reverse DNS does not match SMTP banner error in Exchange 2010

📧 Exchange Server: Solution for “Reverse DNS does not match SMTP Banner” Error

The “Reverse DNS does not match SMTP Banner” error you see when checking your MX records with tools like Mxtoolbox.com can damage your email server’s reputation. This error means that the name your server introduces itself with in the HELO/EHLO command (the SMTP Banner) does not match the Reverse DNS record (PTR record) of your IP address.

To resolve this issue, you must configure the Send Connector setting, which manages outbound mail, through the Exchange Management Console (EMC).

Step-by-Step Solution

You must follow the steps below sequentially:

1. Open the Exchange Management Console (EMC).

2. In the left menu under Organization Configuration, click on Hub Transport.

3. Go to the Send Connectors tab that appears on the right.

4. Right-click on the Connector that sends mail externally (the one facing the internet) and select Properties.

5. In the window that opens, go to the General tab.

6. In the empty field below Specify the FQDN this connector will provide in response to HELO or EHLO:, enter the fully qualified domain name (FQDN) of your email server that exactly matches your Reverse DNS/PTR record.

For example: If your Reverse DNS record is mail.yourcompany.com, you must enter mail.yourcompany.com here as well.

7. Click OK and save the setting.

After making this setting, your Reverse DNS (PTR) record, the FQDN provided by your Send Connector’s HELO/EHLO, and the A record for that FQDN will all mutually validate each other. Congratulations, you’ve saved your reputation!