We investigated reports of SMTP connection timeouts and found that some of our incoming mail servers had accumulated stuck mail-handling processes. These processes were consuming excessive processing power, reducing the servers’ capacity to handle other connections and potentially causing slow responses or timeouts.

Our investigation identified a possible fault in the handling of an SMTP authentication method. Diagnostic checks showed a process attempting to respond after a connection had closed. We are investigating whether this caused the processes to become stuck; the exact trigger has not yet been confirmed.

Actions removed the observed resource buildup, but we are continuing to monitor for recurrence.

We are preparing mail-server software updates and assessing whether they address the underlying fault. We are also evaluating a safeguard to detect and clear stuck processes before they affect service.