(solved) send mail with Rules when a term in multi value vocabulary is selected
I see 2 possible reasons that may cause your problem:


Maybe it's a data type conversion issue. You may be more lucky to get that 2nd condition to work if you'd use a text comparison (= "text_matches")  instead of a data comparison (= "data_is").
Maybe your zichtbaarheids-field is a multi value field?


To further investigate this, just add a "Display a message" (within System) as your very first Rules Action, to display the actual value (using an appropriate token for your field), after you temporary remove that 2nd rules condition (to ensure the Rules Actions are performed). If that doesn't help either, you may also want to (temporary) enable the Devel module, so that you can (temporary) add a Rules Action like "Display a value".