http://www.perlmonks.org?node_id=986010


in reply to Re^2: Send e-mail using perl
in thread Send e-mail using perl

It's the old Perl4-style sub call syntax, and means "ignore prototype" and (if no arguments are passed), "make current @_ visible to subroutine" (perlsub)

Its use is discouraged but it doesn't seem to be harmful. Personally, I just view it as ugly and a hint that "this user learned Perl from tutorials written in 1995"