InfoPath Dev

Hello,

I have button that sets value for two fields, submits data to database and as a mail attachment and then closes the form.

But I don't understand why it starts up all the rules in the form fields? This leads to field values changing and sections closing etc...

Is it normal feature that pressing button activates all the rules in the form?

If there are rules on the fields you are changing, or conditional formatting that involves those fields, those rules and conditional formatting will execute, no matter how their value is set.  That's how rules and conditional formatting work.