Letter mail volume has been on the rise in recent years - the House receives an average of about 112,476 letters a day, and the Senate receives an average of 125,000 letters a day. The increases on both sides of the Capitol are due to the prevalent use on computerized mass-mailings. In many cases, organizations provide a stamped, addressed postcard with the message already written. All the sender must do is sign his mane and put it in a mailbox. In general, Monday is the busiest day of the week, while January through May are the heaviest months.
Regular mail is still better than email.
Write to your own senators or representative. Letters sent to other members will end up on the desk of members from your state. Make sure your zip code appears on the letter. It lets your Senator or Representative know that you live in their district. Write at the proper time , when a bill is about to be discussed in committee or on the floor.