· Which web mail client are you using?
Follow these steps and check if it helps:
a) Click Start, Open control panel
b) Open Folder options.
c) Click on View tab, check mark on “Remember each folder’s view settings”
d) Click on “Apply to all folders” and click “apply” ok
If issue persists follow the troubleshooting steps from KB article and check if it helps:
Changes to the size, view, icon or position of a folder are lost
Registry disclaimer: Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
How to back up and restore the registry in Windows