Really great BUT... Rated 4 out of 5 stars
Great extension if you want to work with email through firefox!!
But i found a bug..When you clear personal information (Ctrl+Shift+Del) and clear saved passwords is enabled, it also clears the webmail accounts you have created.
That's why i give 9.
A more detailed guide to create user scripts would also be very helpful!
I am using firefox 22.214.171.124 and Webmail 1.0.4