There is a small bug in our WebMail program that prevent some user to delete their email. This problem only happen when you set "Number of message per page" to 100.
Follow the instructions below to work around this problem:
1. Login to your WebMail account
2. Click Option and Style...
3. Click Perferences
4. Scroll down to "Number of message per page"
5. Choose either 10, 20, or 50 (do not choose 100)
6. Scroll down the page, and click [Save]
This is confirmed to be known problem of our web mail system, we hope our supplier will soon release a new version to fix this problem.