Can’t send e-mails

This morning I started sending emails to my 774 subscribers. At this moment, only 300 emails have been sent.

I therefore canceled the task and created a new one, with the result that Mailpoet is no longer sending my emails at all!

What is going on and how can I fix this?

(I haven’t changed anything since the last time I sent an email. I checked the settings and cron, but there is nothing wrong there.)

The page I need help with: [log in to see the link]