Summary

Emails are being deferred with the message "550 5.7.1 Service unavailable, Client host [18.216.227.84] blocked using Spamhaus."  for customers using: us2-smtp-api.titanhq.com 

We have already requested a delisting with Spamhaus and took measures to remove the IP from the pool.

Impact

New messages being received by the SpamTitan US2 server will not be affected as we have removed the offending IP from usage. As per the previous emails that received the "550 5.7.1 Service unavailable" the senders were notified with NDRs and may attempt resending them.

Updates

08/04/2024 17:00 GMT+1 - The offending IP has been removed from the Spamhaus list and it is now service emails.