my %emails = ();
foreach ( split(/\%/, $emailcolumn) ) {
  if ( my ($key, $value) = split(/\s*\:\s*/, $_, 2) ) {
    push ( @{ $emails{$key} }, $value);
  }
} # foreach
# do something with %emails

##</code><code>##

%emails = ( 
  SMTP => [ 'makeusbetter@domain.com', ...],
  X400 => [ 'c=US;a= ;p=domain ;o=domain;s=makeusbetter', ... ],
  smtp => [ ..., ...],
  CCMAIL => [..., ...]
          );