install the 'desktop-webmail' package
run this package, found in internet and select one of the providers
(I run gnome shell, so I assume unity is similar)
Now you might have to setup thunderbird (even with bogus names) to get the next part to show up, I DID. Until then, the system info for default mail never listed 'desktop webmail' as a selectable option.
then goto default applications found in system info
set the default mail to desktop-webmail instead of thunderbird or evolution
I run chrome and I also installed the mailto extension and set it to my webmail
some various screen shots along the way.
I also updated desktop-webmail package to version 003 by following this link.
So now when I click on a mailto link, it loads the webmail page instead.if you dont know how, use this:
sudo add-apt-repository ppa:asac/sandbox
sudo apt-get update
sudo apt-get install desktop-webmail
verify that you use a 003 based version using:
dpkg -l desktop-webmail