After installing Symantec Mail Security for Microsoft Exchange (SMSMSE) 6.x on an Exchange 2007 server and enabling Premium AntiSpam there is a significant impact on mail flow.
This problem occurs when all of the following are installed or enabled on the Exchange 2007 server:
- Client Access Role
- Hub Transport Role
- Mailbox Role
- Symantec Premium AntiSpam
The event log contains the following entry:
Source: MSExchange Extensibility
Description: The execution time of agent 'SMSMSESMTPAgent' exceeded 300000 (milliseconds) while handling event 'OnEndOfData'. This is an unusual amount of time for an agent to process a single event. However, Transport will continue processing this message.
This problem is fixed in Symantec Mail Security for Microsoft Exchange 6.0.7. To learn how to download the latest release, read Obtaining an update or an upgrade for a Symantec Corporate product.
If you cannot upgrade to version 6.0.7 or later, you can reboot your server to restore mail flow. Then, to work around the problem, do one of the following:
- Disable Premium AntiSpam.
- Install SMSMSE and enable Premium AntiSpam on a separate Exchange 2007 Edge Transport server.
- Install SMSMSE and enable Premium AntiSpam on a separate Exchange 2007 Hub Transport server that does not have the Mailbox role installed.