Problem

The default SMTP greeting message for MailGate can be changed under Admin UI > Relay Policies > Relay Settings > SMTP Greeting Message. The appliance hostname is also displayed in the SMTP greeting.

When MailGate is deployed in the internal network, it may have an internal hostname, which is different than the external MX record and it does not have an A record pointing to the external IP address due to an internal DNS configuration.

What happens in certain cases is that SMTP servers may not accept connections originating from a hostname advertised in the SMTP greeting that is different than the external MX record. The most common reason for this is a security restriction enforced on SMTP level by the remote party.

Resolution

Given that no other option is available outside MailGate (e.g. network level or remote party change), you may contact Axway Global Support and ask the hostname in the SMTP greeting message to be customized. Please note that this change may not be preserved by product upgrades.