Read receipts in iPhone & iPad email

Is there any way that I can prevent read receipts from being sent out by my iphone? Currently it automatically sends them out.

The issue that I am currently having is that I have read receipts turned off on my desktop computers, so when I read an e-mail on my desktop computers it doesn't get read on my iphone/ipad. After a while it will start sending out "not read" e-mails to the people that sent me the e-mails, even though the e-mails have been read. Just not professional. I would prefer not to have them sent out at all!