if u're not familiar with the registery pleas don't try my solution
maybe u could try using MsgPlusTweak
- download:
http://files.msgplus.net/data/MsgPlusTweak.exe
- select your email adress
- change the option like in the attatchment
but if you don't feel comfortable using msgplustweak, please ask someone with a bit mor experience to help u out.