php and Microsoft's asp are methods of running software on the server -
not in the user's browser.

The only way I can imagine this happening is if the Web-mail system runs
a complex Java applet in the browser, with security settings and proper
configuration so it can read and write the mailbox files in the
appropriate directory on the local computer. Then there would be
synchronisation problems - and contention problems if the "Web-mail"
system was reading or writing these mailboxes while Mozilla /
Thunderbird was trying to read or write them.

It would be interesting to know if anyone has attempted this.

- Robin

List owner and moderator.