I'm not sure how contacting my representatives in the European Parliament over something that I am concerned about, would be spam.
I don't care what party they are from, or what part of the country they are from. They are still my representatives.
They sit there to represent the concerns of their constituents in parliament, and they cannot effectively do that if they do not know the concerns of their constituents.
If you have good ideas for collective action I'd love to hear them, but until then shooting an email can never hurt.
Edit: Just so there is no confusion, I don't think signing a four year old change.org petition is any more effective than directly contacting your MEPs