Europe

Yeah, full contact details in the signature. They never reply, the cowards.

To give a more helpful answer to your question, I suspect the distinction comes in volume, disruption, and actionability - my emails are nothings, just some random citizen venting anger. If I were sending huge volumes to a specific MP rather than one every few months to the villain of the week, they'd probably come down on me for harassment. If I was a known extremist actor like some of the people I organise with (all ALF) or included details indicating I had an actionable plan to harm them, they'd probably treat it as a serious threat.

On the other hand, my parents were communist organisers during the second half of the cold war, so they get cops turning up at the door if they even hint at planning a protest or demonstration on social media.