Symantec Mail Security for Microsoft Exchange (SMSMSE) transport agents fail to run after Microsoft Exchange 2010 RollUp 8 installed.

Products

• Mail Security for Microsoft Exchange

Issue/Introduction

After Microsoft Exchange 2010 RollUp 8 is installed, Microsoft Exchange Transport service failed to load until SMSMSE is uninstalled. Hence SMSMSE transport agents were removed from Exchange Transport Agents
.
When SMSMSE is being reinstalled, installer will fail to install SMSMSE transport agents. The agents cannot even be installed manually by following this document - How to manually install Symantec Mail Security for Microsoft Exchange (SMSMSE) transport agents. Error shown under Exchange PowerShell while installing the agents manually -

The TransportAgentFactory type "Symantec.MailSecurity.Server.TransportAgent.SMSMSERoutingAgentFactory" 
doesn't exist. The TransportAgentFactory type must be the Microsoft .NET class type of the tranport agent factory.

Cause

Microsoft Exchange 2010 RollUp 8 installation failed at some point and causes failure to load/install SMSMSE transport agents.

Resolution

The issue is not product related but environment issue instead.

Workaround:

One known workaround is to Install Microsoft Exchange RollUp 7 instead. However, it is recommended to contact Microsoft Support for workaround / solution.