I have a problem .. I want only email activities to resolve intent ACTION.SEND but beside email I get other apps as well (e.g TubeMate) even though I have set the mime type
In Android, there's no such thing as an email activity. There's also no intent filter that can be created to include only email applications. Each application (or activity) can define its own intent filters.
So when using intent ACTION_SEND, you'll have to rely on the users intelligence to pickhis favorite email app from the chooser (and not TubeMate).