We've resolved the incident and sending via SMTP is back to normal. Any previously failed messages via SMTP would need to be retried. We will continue to monitor and thank you for your patience.
Our team are actively working on resolving the issue. We will continue to post updates until this is fully resolved.
Messages sent via SMTP are being rejected due to an SSL certificate error. Our team have identified the issue and are working on a fix.
Sending via our API is unaffected.