While I can't think of a project off the bat that you might like in order to sharpen your Unix/Perl skills, I think that if you want to relearn these things (Sendmail, DNS, etc) then you should either get a book, download the software packages and read the READMEs, or read the Solaris docs at docs.sun.com.

Still I think that Sendmail, NFS, and DNS are poorly written insecure packages and you might consider looking at some alternatives at cr.yp.to.

Considering that you were expert at using these technologies it should be no problem for you to refresh yourself.

metadoktor

"The doktor is in."