Email messages are not delivered.
NOTE: The character set name in the message may be different.
The example error message above is ISO8859-15. This is not a valid character set. The valid character set is ISO-8859-15 (see this article: http://en.wikipedia.org/wiki/ISO/IEC_8859-15).
This is caused by an Symantec Mail Security for Microsoft Exchange receiving an improperly formatted Character set name in the email message. For example, the invalid character set name is ISO8859-15 and the valid character set name is ISO-8859-15.
This issue is fixed in SMSMSE 6.5.5. Upgrade to 6.5.5 to resolve this issue.
NOTE: This workaround is only applicable to customers that do not use Symantec Premium Antispam.
To check if you are using Symantec Premium Antispam:
Disable the SMSMSESMTPAgent which is responsible for handling Symantec Premium Antispam scanning. These steps should be performed on all Hub and Edge servers experiencing the problem.
Steps to check if message has a improperly formatted Character Set:
1. Open Exchange Management Console.
2. In the left-pane select Toolbox.
3. In the right-pane select Message Tracking.
4. If prompted, choose whether to check for updates during startup and whether to join the Microsoft Experience Improvement Program then Go to Welcome screen.
5. Verify the EventID is set to Receive and the Start and End times cover the time of the Application Event log entry.
6. Click Next.
7. You will see a message with a subject that resembles =?ISO8859-15?Q?Subject?=.