Jade,
Edit parameters for your notifications package. Would only work for Maildir format mailboxes though.
EmailDomain - should be self explanatory
EmailQmailQueue - the standard Maildir that the user running your nsd process can read
EmailQmailQueueScanP - just set this to 1 to enable scanning
EmailReplyAddressPrefix - a catch all prefix for your notification emails. This is used in constructing the reply-to address of your outgoing mails sent via notifications package. A corresponding catch all email must be made on the system as well, depending on the MTA you are using, this could be done via .forward files, qmail alias files, etc. This should deliver to EmailQmailQueue.
