Usually it takes a maximum of 28 days to reply to an email. However, the reply will be based on your request. For example, if you are asking how long it takes to finalize your application, and the deadline of your application has not been passed, they may not even reply to it. However, they usually send an acknowledgement letter of two or three lines saying that your application is in process. Be patient and pray to God! Things will be OK and going alright! Wish you the best...