Open Relay questionnaire

[Eric Walters]

I am looking for some input on this as it relates to virtual hosting.  My
users are all remote and I am trying to find a happy medium between security
and user-friendliness.  Is there a way to ensure that unless the rcpt to: or
mail from: contain a local domain qmail will not deliver the message?

So far I have implemented relayclient but that is a real pain to administer
and an inconvenience to my users.

SMTP Auth pros and cons?

Any suggestions so I don't reinvent the wheel?

Thanks,

Eric