From Mandriva Community Wiki

Here's the 'trick'... in each browser, enter the URL about:config

[edit] about:config (Mozilla/Firefox)

Then, add the following entries via right-click in the main part of the window:

  right-click->New->String
    network.protocol-handler.app.mailto [OK]
    $HOME/mailto.sh [OK]

  right-click->New->Boolean
    network.protocol-handler.external.mailto [OK]
    true [OK]

Then, $HOME/mailto.sh is this simple script (assuming sylpheed-claws as the MUA):

#!/bin/bash
cat > ~/mailto.sc <<EOF
$1
EOF
sylpheed --compose "$1"   # security warning: quotes required

The 'cat' part just copies the data the browser is passing to the mailer into $HOME/mailto.sc so that I can verify the mailto link at least tried to call the mailer... for example, hitting the mailto link on my home page shows that this was passed from the browser:

mailto:[email protected]?subject=pfortin.com Web Site

This way, I could change my mailer in one place for all browsers... (I've only tested this with Mozilla and FireFox....)

[edit] Kontact / Kmail

For Kontact/Kmail just replace

sylpheed --compose "$1"   

with

 
     kmail "$1" 

or if you want to skip the extra script change the

  right-click->New->String
    network.protocol-handler.app.mailto [OK]
    kmail [OK]