I’m a former Legislative Director (and also a former Legislative Correspondent), and I disagree with the Emily with all due respect. If you want to get the attention of a Member of Congress (Member), first get the attention of their staff. Here are three great ways to do that:

Correspondence from non constituents almost always gets sent over to the appropriate representatives office via a zip code look up. The term is “buck mail.” Especially if you emphatically disagree, they will just put your letter back in the envelope and buck it over to your guy/gal.