SonicWall error message - 554 No SMTPd here

Error Message

554 No SMTPd here

Emails are blocked by SonicWall with this error message.

The error means SonicWall considers one of Mail-List.com's IP addresses to have a flagged reputation. (potentially problematic IP).

How to Fix

In SonicWall, reputations are considered at the connection level. Add all Mail-List.com's IP Addresses as Trusted Connections.

For a complete list of Mail-List.com's IP Addresses, please click here.