I am currently using Magento 1.9.x and ran into a problem. It is not sending automated new order e-mails out. But the weird (in my opinion is), is it sending e-mails when I click the 'send mail'-button at the order screen.
When I browse to an order, it actually says 'confirmation e-mail not send'. When I send it manually, it changes into 'confirmatin e-mail send'. So the sytem knows it's not sending out the e-mails.
What can I do? The .cron seems to be working fine, as it actually tells me that the last heartbeat is x minutes ago and I can see the cron-timeline. It's not giving me any red messages either.