Write a letter to your senator by finding the senator's address on Senate.gov, writing your letter, attaching appropriate postage and mailing the letter. If you want a response, you must include all of your contact information with the letter. Most senator's offices also accept email, but physical letters are more likely to be read and to receive a reply.
Use the proper form of address when writing your letter. While the formal method of addressing a letter to a senator uses "The Honorable" before writing the senator's name, writing "Senator" instead is also acceptable. Use the proper form of address both when addressing the envelope and in the introduction to the letter.
Use a professional tone when writing your letter, and pay attention to grammar, spelling and sentence structure. Do not worry about making your letter suitable for publication, but keep in mind that a literate, professionally worded letter is more likely to convey your opinion effectively and to receive a response.
Focus on a single issue when writing your letter. If your letter concerns a particular voting measure or bill, write that bill's correct name and number on the back of the envelope. Senators or their staff are more likely to read letters that focus on single issues, particularly those currently up for voting. If you have concerns about multiple issues, send separate letters that focus on each one. Tell the senator what action you want her to take on the specific issue, rather than just expressing your feelings on the matter.