If you are having issues with your emails not sending in admin, or the contact form not sending emails; then this might solve your problem.
I noticed after 2 hours of debugging that i was using an email@example.com email which was preventing the form and admin to work correctly. Try creating an email that includes your website name i.e firstname.lastname@example.org once you create an email on your websites hosting account use that email in your admin->settings->store email. I also went to the mail configuration tab and entered it into the mail parameter -f email@example.com .... things began to work.
I'm guessing this new version assumes you will be using an email that is linked to the site. Not sure if other versions had this same requirement, but if you overlooked it and happen to be using an email thats not @yourwebsitesname.com then try what i did.
Hopefully this solves some one a head ache.
Also ensure your admin - > systems - > settings - > edit settings - > mail tab - > bottom page contains check marked options to the route where emails should be sent in the mean time.
The most generated errors being found on Opencart forum originates from contributed programming. The increased counters are caused by posted redundancies of the same solutions that were already provided prior.