[vchkpw] vmoduser usage

I'd like to know the difference of vmoduser options listed below. -s ( set no smtp access flag ) -r ( set no external relay flag )

[vchkpw] How to back up all incoming messages.

What I want to realize is that all incoming messages would be saved to the appointed directory. I performed the following operations in order to all incoming messages are also save to /usr/local/vpopmail/domains/bar.com/foo/Maildir.bak, but the original message is doubly written down in the saved