Error: "554 5.7.1 Rejected message by MTA, EHLO domain does not exist in DNS"

Products

• Messaging Gateway

Issue/Introduction

Messaging Gateway is unable to deliver messages to one or more destination domains. Message audit logs for the failed email delivery shows the following SMTP response from the destination mail server:

554 5.7.1 Rejected message by MTA, EHLO domain does not exist in DNS

Environment

Messaging Gateway: All versions

Cause

The hostname presented in the SMTP EHLO greeting does not have a valid 'A', 'AAAA', or 'MX' entry in the DNS

Resolution

1. Log into the Control Center as admin.
2. Go to Administration > Configuration > hostname > SMTP > Advanced Settings > Delivery.
3. Ensure that the MTA host name value at the top of the page is resolvable in the public DNS to an IP address or matches one of the MX records for the domain
4. Click Continue
5. Click Save