is it safe to have two backed used for the same user?

hi everybody

I wonder if it is safe (and wise) to have two passw-user databases for the same one user. I'm thinking, mail to me via pam mail to me@this.domain via ldap

whole Maildir would be essentially the same one storage target, I see permissions have to be mangled, available to write for both vmail and actual uid.

what do you think? Is it how it's done?

regards