(Email is very hard to use as back-and-forth messaging and is more for one-time official stuff, and one can't tell whether or not an email has been received or read.)
Facebook Messenger: "Peter Voluntaryist Walker" on Facebook and best to go to Facebook Messenger and send me a message and that way you don't have to be a FB "Friend . FBM is the best for back-and-forth messaging and one can tell whether or not the other person has read one's message and it has many more options than cell texting.
Smoke Signals: Three puffs, wait three minutes, RePete.
Snail Mail: Peter Walker, 330 E Costilla St, Colorado Springs, CO 80903 (Mailing only address and I live near the intersection of Wahsatch Ave and E. Bijou in Colorado Springs, CO)