Setting Up Custom SMTP and EHLO Banners

Axigen Documentation

Depending on how you setup your hostname at the operating system level, you may need to overwrite the SMTP and EHLO banners.

Please note that the good email server practices require that SMTP and EHLO banners be the Fully Qualified Domain Name of the server.

Following the recommendations in our dedicated knowledge base article: How to setup Axigen to use a specified FQDN when sending emails (EHLO banner) / modify the default SMTP banner for incoming connections, perform these configurations.

Checking the SMTP banner

After configuring the Acceptance / Routing Rule for setting the SMTP banner, perform the following check:

Checking the EHLO banner

In order to be able to inspect the EHLO banner presented on outbound connections from your email servers, you have two options:

  • Change the Axigen SMTP Sending service log level to Protocol Communication and inspect the logs 

  • Perform a TCPDUMP of your outbound SMTP connection

In order to change the Axigen SMTP Sending service log Level to Protocol Communication, perform the following actions in WebAdmin:

  • Log into WebAdmin

  • Go to "Services → SMTP Setting"

  • Drag the slider in the "Log Level" section to Protocol Communication

  • Click "Save"

Open a terminal and issue the following command:

Then, log into WebMail as a user and send an email to an external domain. 

You will notice:

You will notice the line containing >> EHLO This is where the value that you configured for the EHLO banner should be reflected.

The FQDNs defined in the SMTP and EHLO banners should be properly configured in DNS, as described in the DNS Prerequisities page.