No formal for "mon pote". French, french Canadian (if someone from Quebec can confirm) and most french speaking African would skip the "my friend". I guess in a post mail (people still write those) you can use it, but it's very old fashioned. That how I imagine the Princess of Cleve would begin a letter to Voltaire: "Voltaire, mon ami, c'est fantastique d'être ici, à Paris". I guess the point is: if it's really your friend, you can use the informal "mon pote". ("poteau" is the original term that was shortened in "pote" and became the most used one) I dont want this to be a lecture on French. It's just, reading your post, It come to my mind, that french really are adverse to intimate speaking with stranger. And everybody admit, even when we all hate you, that Americans are very kind to strangers. So keep saying "mon ami" to whoever you want. French should change their cold way of speaking :)