To put limits on file names for incoming email attachments, configure rules in the SMTP-Incoming proxy action ruleset. To put limits on file names for outgoing email attachments, configure rules in the SMTP-Outgoing proxy action ruleset. You can add, delete, or modify rules.
If you modified a predefined proxy action, when you save the changes you are prompted to clone (copy) your settings to a new action.
For more information on predefined proxy actions, see About Proxy Actions.
About the SMTP-Proxy