How to ask my professor to write recommendation letter for me? Now I'm in a community college and I am trying to gathering recommendation letter to apply to graduate school.(I have already got my bachelor degree). I performed well in calculus and got an A in that course. After i got my grade, I wrote a thankful email to my professor and he replied me that I am the top student in his course. I thought he is nice. Therefore I asked him whether he can write me a recommendation letter to me by e-mail but there is no-reply. I considered if he didn't see my email, so I went to his office and wanted to see him in his office hour. His office hour was posted on the wall and on the schedule he said if anyone want to see him please notice him ahead of time. So I e-mail him again to ask for an appointment. Here is the content:

Dear Prof XXX:
It's XXX, a student who finished your calculus 1 last semester. I went to you office yesterday and record your office hour on the wall. Would it be possible to meet with you next Monday 11 am (office hour) about whether you can help me write an recommendation letter?
Regards

He didn't reply me. I almost lost my confidence. I don't know whether I need to go to his office directly. I am afraid it's impolite or disrespect. And I don't know  if he don't want to do it, why he praise me in the first thankful note?
Hope anyone can help me.
Your e-mail looks okay as an appointment mail. There are a few possibilities. The professor may be busy with some important things he has to do. He may be on vacation, not available. Please don't lose your confidence yet. You probably should wait a few more days for him to reply. 

It is also possible that he didn't think an A in Calculus I is good enough for him to write a recommendation letter for you. He may want to wait until you get another A for Calculus II and then write a good recommendation letter.

However, depending on which field you are going to study in graduate school, the professor who taught you Calculus I may not be a good candidate to write you recommendation letters.

You already have Bachelors degree. I think the recommendation letters written by the professors in the university where you graduated from, who had more working experience with you would be more helpful for your graduate school application.