I am very happy to receive from you, how is it going for your new job? I am writing to apologise to you that I cannot meet you on this Sunday.
Well ... these lines have several issues. First, they lack clarity and sound confusing :(
I am very happy to receive from you
... What does this mean? what did you receive from your friend? Or is this what you want to say;
I was pleased to receive your letter.how is it going for your new job?
.... this is too very confusing :(
I am writing to apologise to you that I cannot meet you on this Sunday.
This is bad news for him, so you need to say that very politely and diplomatically so that he would not be hurt. Show this person how sorry you feel for not being able to meet him. The above sentence is pretty abrupt and sounds a bit rude too.