I took a class with a professor who was very impressed with my assignments, to the point where he asked for me to stop by his office and discuss my potential career in writing. During this appointment, he offered to write me any recommendation letters I might need. Overall, I thought this appointment and my overall experience in this class went well.
That was the only class I took with this professor, and it's been roughly a year since we've been in contact. Several months ago, I wrote him asking for a recommendation letter, and briefly referenced our past meeting. I got no response, even after a reminder email I sent him several weeks later.
Once again, I find myself needing a letter of recommendation, and, if this professor is actually willing, he would be a perfect reference. However, considering his lack of response in the past, I'm not sure if I should email him again.
Additionally, my class with him was actually the last class he taught; he's now a professor emeritus, so I'm not sure if it's appropriate to contact him at all. There's a second professor emeritus in my department who regularly writes me letters of recommendation, but I don't know if this is par for the course or if that particular professor is just more amenable than most.
Should I try contacting this professor, even though he's retired and had no response to my emails several months ago? If so, how should I contact him?