Business e-mail 1

Dear Sirs;

Thank you for your facsimile of August 19, 2014. However, we have not received the confirmation of the documents yet. ('However' is a connecting word. It is used to provide a transition from the previous sentence to the next sentence. This is why I have moved this sentence to form part of the first paragraph)

We would be grateful if you could confirm via email that you have sent the confirmation of the documents that you sent it also via mail. 

Regards,
Natsu

Your written English is very good. I changed the word order in the final sentence so that it would be gramatically correct. Keep up the good work.