+0
I should use the active or passive voice here? Which one sounds more common and natural?

1. Your fax of the quotation has been received. OR

2. I've received your fax of quotation.

- Is the preposition "of" here used correctly?

Thank you!
+1
I suggest that you be direct:

We have received your quotation fax.
Comments  
Students: Are you brave enough to let our tutors analyse your pronunciation?
Mister Micawber,

Yes, absolutly! You are right! My sentences are just too "complicated"!!!

And is it right to say, "I'll well proceed your order."?
No, that's not natural. Do you mean 'I'll process your order promptly/immediately/in a timely manner/ with care'?
Mister Micawber,

Yes, I see! Your suggestion is just the way what I want to say!!!

I always have this problem in English. Very often, I just don't know how to make good sentences. Any comments for me?

Thank you very much!
Students: We have free audio pronunciation exercises.
I cannot say that you repeatedly make any specific mistakes. It is just a matter of reading and experience. Try to find business correspondence websites on the internet, for instance, and read the sample business letters that they present.