I've done a MSN Messenger client so I know this protocol. So here is a code I modified from yours.

Code:
alias nc {
  sockclose nc
  sockopen nc messenger.hotmail.com 1863 
}

on *:sockopen:nc:{
  if (!$sockerr) {
    sockwrite -n $sockname VER 0 MSNP7 MSNP6 MSNP5 MSNP4 CVRO
  }
}

on *:sockread:nc:{
  sockread %tempdata
  if (%tempdata == VER 0 MSNP7 MSNP6 MSNP5 MSNP4) { sockwrite  -n $sockname INF 1 }
  if (%tempdata == INF 1 MD5) { sockwrite -n $sockname USR 2  MD5  I  %mail }
  if (XFR 2 isin %tempdata) { echo $replace($gettok(%tempdata,4,32),:,$chr(32)) }
}