First of all DMZ is not recommended at all coz it makes ur compter open for attacks.
@mayank717 you have to change the settings u have done. eMule by default uses 2 seperate ports one for TCP and one for UDP(u have configured external port 4662 and internal port 4672). Just make 2 seperate entries for eMule in virtual servers one with TCP-4662 and second with UDP-4672. While doing both these entries make sure that external and internal ports are same. Here is how to do port forwaring