Currently I send my mail using PHPMailer using Mandrill's instructions.
My email is sent successfully and goes into my gmail/hotmail inbox.
I clicked and open but had no idea why the chart on my Outbound Activity didn't show I had open/click the email. Is it needed to be wait few days only the data reflected on my graph?
I also checked my settings on Mandrill, I did track the open/click email on my settings.