this is really generous and should definitely be followed up on. tons of email is easier to ignore than a cascade of real letters.
A call or a letter/email you write and send yourself will be much more impactful.
The amount of attention your representatives tend to give your issue is directly proportional to the amount of time you can force them to spend listening. You can filter an email; you can skim a letter; you have to listen to a call all the way through. The best thing, though, is to set up an appointment, and talk to them in person.
It's almost a truism: if you want to show that you care... spend the time to show that you care. I actually think it's really cool that you can walk right into the office of your Congressman or Senator. Obviously you won't get past the interns if you don't have an appointment, but still... pretty cool.