Digest messages not accepted by some mail systems due to UTF-7 encoding

This article applies to:

• Trustwave MailMarshal (SEG) 
• Trustwave ECM/MailMarshal Exchange 7.X
• Message Digest functionality

Symptoms:

• Some email servers do not accept MailMarshal digest messages for delivery
• Some email clients do not properly render the content of MailMarshal digest messages

Causes:

• Digest messages in the affected MailMarshal versions allow Unicode text in the body (subject lines of digested messages).
• This enhancement allows users to view message subjects in non-european character sets including CJK (Chinese Traditional & Simplified, Japanese, Korean, and Korean EUC) as well as Vietnamese, Thai, UTF-7 and UTF-8 encoding.
• Some software does not accept the encoding of these messages.

Workaround:

If you encounter this issue, you can apply the following Registry entry to revert to an earlier version of this functionality. Unicode characters will not be available. 

• In MailMarshal 10.0 and above, on the Array Manager edit the file arraymanager.config.json and add a new value:
  • Name: DisableUTF7Digest
  • Type: Boolean
  • Value: true
  • To add this value, before the closing brace at the end of the file, add this line including the leading comma - note that Json is case sensitive:
    ,"DisableUTF7Digest" : true
• In MailMarshal 8.X and below, open the Registry Editor on the Array Manager. Within the base registry key, navigate to \Manager
  • In version 8.X: HKEY_LOCAL_MACHINE\SOFTWARE\Trustwave\Secure Email Gateway\Manager
  • For information about the registry location for each version, see article Q10832.
  • Enter a new DWORD value named DisableUTF7Digest with value 1.
• Save your registry settings or configuration settings.
• Commit the configuration changes and restart the MailMarshal Array Manager service.