sub isend {
  my $line = shift;
  my @terminators =
  [ qr!#=3D=3D=3D(?:END|end)!,
    qr!#===(?:END|end)!,
    qr![-]+_=_NextPart_!,
    qr!1===(?:END|end)!,
    qr!#---(?:END|end)!,
  ];

  foreach my $ending (@terminators) {
    return undef if $line =~ $ending;
  }
  return 1;
}

##</code><code>##

@terminators = [ [foo, bar], [baz, bletch] ];
# an array of array refs, right?