You are absolutely correct.
Phone calls are excellent, Faxing a letter is good too.
US Mail is very slow to reach Congressmen, but a well-written and signed letter can't hurt either.
Most of the Congressmen / Congresswomen cannot be emailed if your zip code is outside of their district - I found that in most cases, the email form on the house.gov site blocks you out. However, I was able to email Markey, Fleming, Coffman, and Holt. I also sent an email to Southerland thanking him for his stand against HR 511 and his outstanding assessment, from top to bottom, of this bill.
Show your allies some gratitude!
If we value the hobby, we must continue to pressure these legislators.