Email sending Problem

[jailani2k]

am using Prestashop version 1.6.1.6, from my website When I order first time email sending without any problem, I got Order confirmation email and Order status email, When I Order second time with in 5 minutes Order page take around one and half minutes to redirect to confirm page, When I remove the order confirmation email from coding, its redirects order confirmation page soon. I think problem with Order confimation email sending. But When I order first time its working next time only I got this problem. When I try to Order from Other system browser same thing happening first time its loaded quickly and send order confirmation email. when I Order second time its gets time to redirect order confirmation page, some times sending confirmation email some times not. I dont know how to figure out the Problem. am using SMTP to send emails, I changed to send emails options with PHPs mail option But email not sending. in SMTP option only sending emails. 

Edited August 10, 2017 by jailani2k (see edit history)