If you have a Sony Ericsson X10 mini phone you might have noticed that the contacts application is custom. In other words they have not used the Android default contacts applications, but written their own (probably so they could include the timescape button in the upper right corner).
The problem with this is that they have removed the "Send calls directly to voicemail" feature. This is a good feature if you are bothered by some contacts. It is possible to use this feature anyway:
1.Run RoadSync Mail or RoadSync Calendar application. It is a third party software bundled with your X10 mini. Complete the product registration by entering a name and an e-mail address. I'm not sure if it is necessary to actually configure an Exchange account or if it is enough to just complete the product registration.
2. Exit RoadSync and return to start screen and start the Sony Ericsson contacts application
3. Choose a contact and scroll down and press Edit
4. You will now be presented with an option on how to edit the contact:
5. Now you will enter the normal Android default contacts editor:
6. Test it. Try to call your phone with the changed contact. For me the call was not sent to voicemail, I got a busy tone. This is good enough for me.
Note 1: When you get an incoming call you will not get any notification that someone is calling you. You can however see that someone has tried to call you in the call log.
Note 2: Be a bit careful when clicking around in the Android default contacts editor. It is easy to delete all contact phone numbers by pressing the red minus icon in conjunction by pressing the back key; the contact will automatically be saved.
Note 3: If you accidentally have pressed the "Use by default for this action" checkbox you can clear this by opening Settings -> Applications -> Manage applications -> find you application that is default, scroll down and press "Clear defaults".