It is always sweet when graduates send an email just to say they’re thinking of the class they had with you. I know they’re busy with their new lives, and I wouldn’t expect them to take the time — and that makes it all the more appreciated.
Hi Mr. Castro,
I hope everything is going well with AP Psych and World History 2. I just wanted to let you know that I’m taking general psych this semester and it’s pretty boring because I know all about how crazy Freud is already. I’m sitting in the library with Mia and we thought we would send a selfie and let our favorite teacher know that we miss him in a noncreepy way. Thanks for being an awesome teacher last year and helping me pass.
Thanks,
Sabrina & Mia

Sending a picture is just icing on the cake.