my $string = qq|sean\@gmail.com, "richard" <richard\@gmail.com>, "john" <john\@gmail.com>, <jack\@gmail.com>|;

##</code><code>##

 my @email = split(/\,/,$string);
 for my $var( 0 .. $#email )
 {    print "$email[$var]\n";
      .....   # put additional code here 
 }