I used to play ACCF a long time ago and now I am back to play again. How can I get different fruit for trees now?

mail letters to your villagers containting fruit. In return, they may send back foreign fruit but it isnt guaranteed

Make sure to just say "Please send fruit." in your letters. It will take awhile but I was able to get all my fruit that way. You will get other things as well, and sometimes they'll only send back a letter, but eventually you will get all of your fruit if you keep on trying.

I have send many letters and finally one of my villagers send a peach now if I can get an apple and cherries. Thank you