I've actually implemented these package parameters for our stuff, however, we use SendmailBin instead of SMTP. The difference in that regard is pretty minimal, however I would strongly suggest that ns_sendmail not have a different behavior than mail-lite. This results in confusion when some messages are being logged or redirected while others are sent to the recipient. This is actually part of the reason I implemented the changes. I'm happy to provide you with the changes I've done, though.
The parameters I added are:
EmailDeliveryMode:
Must be one of: "normal", which sends messages via SendmailBin, "log", which logs all messages instead of sending, "redirect", which sends all messages to address specified in EmailRedirectTo parameter, "debug", which logs every message after sending, and "bcc" which sends a copy of every message to the address specified in EmailRedirectTo parameter.
EmailFilter:
Filter for the To address for allowed recipients. All other recipients will be removed from emails. Wildcards (*) may be used. Example: mailto:*@example.com or mailto:sysadmin@*.com
EmailRedirectTo:
Comma-Delimited list of addresses that will used for EmailDeliveryMode of "redirect", "debug" and "bcc".
