The email provider has informed us that the services in Cluster B are stable and this incident has been resolved.

Update from the email provider: "Monitoring - Our engineering team has implemented a fix. As a result, service performance has improved, and we are continuing to closely monitor the environment to ensure stability."

We have received a new report from our email provider and the incident seems to still be active: "We are currently investigating reports of email login issues affecting some customers on Cluster B - Webmail/IMAP/POP again. Our team is actively working to identify the cause and restore normal service as quickly as possible. We will provide further updates as more information becomes available."