Bulk mail using exchange server 2013 and 2016

Question

Hi i need help regarding number of mail sending per hour.

 

as earlier we were deployed exchange 2007 in our organization in that case we ware sending approx 10000 mail par hour with 20kb of attachment but now we have updated into exchange server 2013 and 2016 and we are able to send same mail only 700 approx mail per hour

 

please help how to increase limit up to 10000 per hour with 20kb of attachment with exchange server 2013 and 2016