I have DC at two different primary schools (for complicated reasons).
At one, the class teacher gave parents her email address (obviously her school one, not her personal one) at the start of term and told us to use it if we needed to communicate with her. At the other, we were told not to email the staff directly.
I just wondered which is common practice? I'm not someone who is constantly in contact with the teacher (in fact I've never used the email address I was given), but I do like the idea of being able to if I need to, without having to make an appointment or communicate via the school office.