Web Mail Center

Use an interface that is split into panes.
This interface is more user friendly and attractive, but requires a web browser that supports 'frames' and 'cookies'.

Use a single-pane interface.
For old or 'thin' web browsers. More cumbersome to use.

Don't cache output.
Check here to set Web Mail to mark all output pages as expired so that they will not be cached, for increased security and privacy. (Some web browsers may not honor page expiration directives.)