It seems like everything in the zone "spf.nssi.telus.com" resolves, regardless of further DNS labels. So yeah, I'd say every host with any IP is allowed to send mails as anything from telus.com. That's a bit unsettling.
Indeed, the DNS records are gone. They had a tweet[1] 1 hour or 2 ago how they are working on it. I guess someone got phoned on his sunday to fix it. I'm hoping for a further update from their side what happened.
