Email Security.cloud

We are a small bulk sender of emails.  Due to a company name change, the sending domain was changed.  Prior to the domain change, there was never an issue with mail not being accepted.  Once the domain changed, we are receiving messages such as:

attempt connect using MX cluster2a.us.messagelabs.com./85.158.139.103
connecting from  {xxx} to target domain  {xxx}

 Connection failed: java.net.ConnectException: Connection timed out: no further information: closing connection.
Unable to connect to any MX for target domain.

The sending IP did not change, only the sending domain.

Is there a method of addressing this?

Instances where connections to the Symantec.Cloud infrastructure fail can mean several things, from an incorrect MX configuration of the recipient, to a change in their anti spam configuration, etc. The most effective way to have these event investigated is to open a dialogue with the recipient.

The Cloud service is largely monitored and configured by the client directly. They ultimately are in control on what comes and in and goes out through the service. Having them investigate will give you the most information on the reason the emails are not making it through.