Disclaimer:
Warning
Serious problems might occur if you modify the registry
incorrectly by using Registry Editor or by using another method.
Modify the registry at your own risk, Every effort has been made
to ensure that registry edit instructions are correct and safe. Internet Fixes cannot be held responsible for any damage done to your
system by using this guide.
Before beginning this guide,
please do
this
Click
,
then
.
Type regedit then click

Navigate to the following key:
HKEY_LOCAL_USER\Software\Microsoft\Windows\
CurrentVersion\UnreadMail
Then Right click
somewhere in the right hand window , and click New
then Dword. Name the DWord
MessageExpiryDays and give it a value of 0
to disable, 3 to enable.
Reboot your computer.