Active Incident

Updated a few seconds ago

Deferred emails to Microsoft TenantsDegraded Performance

Incident Status

Degraded Performance

Components

Email Inbound, Email Outbound

Locations

Frankfurt, Hannover


June 2, 2026 17:32 CEST
June 2, 2026 15:32 UTC
MONITORING

Microsoft is working to resolve the observed issue as soon as possible. More Details can be found here: https://admin.cloud.microsoft/#/servicehealth/:/alerts/EX1331830 We are monitoring the situation closely. Other services are not affected.

June 2, 2026 16:48 CEST
June 2, 2026 14:48 UTC
INVESTIGATING

We are currently observing reports of emails being deferred when the receiving Host is a Microsoft Tenant. From our current findings this seems to only affect German M365 Tenants. The behavior can be identified by following SMTP Code: 421 4.3.2 The maximum number of concurrent connections per resource forest has exceeded a limit, closing transmission channel Affected emails are in the deferred state. We are trying to deliver inbound deferred emails for up to 7 days and outbound emails we are trying to deliver up to 24 hours. Other services are not affected.

AI Recipient Validation




Operational

365 Permission Manager




Operational

365 Total Backup




Operational

365 Total Protection




Operational

365 Multi-Tenant Manager




Operational

Advanced Threat Protection




Operational

API




Operational

Control Panel - General




Operational

Control Panel - Config / Deployment




Operational

Control Panel - Email Live Tracking




Operational

Control Panel - Backup & Compliance Services




Operational

Email Signature and Disclaimer




Operational

Email Inbound




Degraded Performance

Email Outbound




Degraded Performance

Email Continuity




Operational

Email Archiving




Operational

Email encryption: Websafe




Operational

Email encryption: S/MIME




Operational

Hornet.email




Operational

IMAP/POP3 Services




Operational

Mailbox Migration Tool




Operational

Security Awareness Service




Operational

Ticketsystem




Operational

Web Filter




Operational

Website




Operational

External Services

Zendesk

Locations

Scheduled Maintenance

[HSE20260613-01-M] Scheduled Maintenance: Control Panel 6.57.00Planned Maintenance

Schedule

June 13, 2026 10:15 - 12:15 CEST
June 13, 2026 08:15 - 10:15 UTC

Components

Control Panel - General, Control Panel - Config / Deployment, Control Panel - Email Live Tracking, Control Panel - Backup & Compliance Services

Locations

Georgia, USA, North Virginia, USA, Switzerland, West Europe, Global

Description

We plan to release Major Version 6.57.0.0 of the Control panel on this day: 2026-06-13 10:15am CEST Due to the nature of this release, there might be functional upgrades and updates alongside with Bugfixes. The Control Panel won't be available during the maintenance window. Other services and email flow will not be affected by this maintenance.