email address format not recognised

I just had a rash of spam registrations today.

The records did not show up in either the approved, spam or firewall CT logs

I tried to add the email addresses from my user table to the CT blacklist but about half of the email addresses would not add to the list. The system reported a number of the addresses as unrecognised. I wonder if this is why they got through the filter.

They had a similar structure as follows:

suzy@a.thailandmovers.com, inge@a.wirelesschargers.xyz tabby@a.cooldown.ink dehlia@a.president.institute tedi@a.helpmeto.bar demetra@a.lifesaver.bar teressa@a.cooldown.ink

Is this an exploit that should be filtered for?