I'm not a native English speaker. My understanding of the meaning of 'OK" is to acknowledge what has been said. In other words, I think it means "I get it" or "I agree" when you say "OK" as a response to others. I never thought "OK" could be a word making others feel disrespectful. Recently, the thing happened to me make me wonder whether "OK" sometimes make others feel impolite and disrespectful.
In my reply email to one of my teachers, a professor in our department who is also not native English speaker, my sentence of "OK, I understand." made him fell very disrespected and unhappy. I feel very sorry for this. I'd like to know whether it is an appropriate way of using "OK" in my reply. The context is as below:
My first email to my teacher: I introduced myself and explained that I'd like to ask his help for my problem. Then I explained the problem I met. Finally, I said I felt very sorry to trouble him because of my own careless. I expressed my sorry again and my thanks.
The reply from my teacher: He told me my problem would be solved.
My reply to my teacher: "OK, I understand. I'm very thankful for your help. Thanks again for your kind help."
Then my teacher thought "OK" was not appropriate herein and it made him feel disrespected.
I'm wondering whether "OK" is a suitable expression herein?
I found some explanations of "OK" in he community. For example, "OK" is used when you are trying to convey that you have received and understand the information. It can just indicate acknowledgement of what's been said, and it doesn't always mean anything more.
In addition, is it position-dependent when using "OK"? When it comes to the students, is it appropriate to use "OK" in the reply email to his/her teacher?
Any suggestion would be very much appreciated.