>I have qmail installed on several machines using Redhat 5.2
>Currently passwords are not shadowed.
>Will qmail be affected if I shadow the passwords
I believe you will have to recompile the checkpassword program.
Within the INSTALL it says that to install shadow support with linux you must
uncomment two lines within the checkpassword Makefile.
With RH 5.0 I found that I had to then edit one of those lines to read -lcrypt
instead of what was in there.
e-mail me privavtely if you have trouble. - eric