We are currently working with our external provider to resolve emails being incorrectly marked as spam when leaving the servers.
Please submit a support ticket if you are receiving bouncebacks indicating "550 The content of this message looked like spam", we'll review and get our provider to manually release the message(s) involved so they get out to the recipient.
We hope to have an update if not resolution on this shortly.
Our external provider has advised that SpamExperts has put a resolution in place which should have mail behaving as normal once again.
Thanks for your patience and understanding throughout this event.
Please submit a support ticket if you are still experiencing issues.
Digital Project Manager & Support