Why not use the same decode way for the LocalPart as the way for the Domain Name in the IDN

Hello!

    Why not we use the same decode way for the LocalPart as the way for the Domain Name in the IDN.
    For example in this way my name 董晓荔 will became xn--1jvp95dgxa,and now I have got some Free mail used
this name. One of these is  xn--1jvp95dgxa <at> 263.net.  
    Then I can use my Email address in Chinese Laguage: 董晓荔 <at> 263.net
    Thanks..

With best regards, Xiaoli Dong.  E-mail: dongxiaoli <at> cnnic.cn