This article explains how to maintain email delivery continuity during an Opensense outage. It outlines Opensense’s redundancy design, monitoring options, and detailed steps to temporarily disable both the Outlook Add-In and server-side mail flow rules in Microsoft 365 when required.
Service Reliability and Redundancy
Opensense maintains a 99.9% uptime record spanning more than 12 years. Its infrastructure is built for high availability and redundancy, ensuring uninterrupted mail operations even during temporary disruptions.
Redundancy via Server Distribution
Opensense operates across 23+ globally distributed servers. This distributed design allows other servers to automatically handle traffic if one goes offline, ensuring service continuity.
To avoid mail flow interruptions, confirm that Opensense’s IPs are whitelisted in your firewall. See the IP Whitelisting Documentation for more details.
Monitoring Service Continuity
Stay updated during any disruption by subscribing to the Opensense Status Page. It offers:
Real-time system health updates
Outage notifications by service region
Historical incident logs for transparency
What Happens During an Outage?
Email Handling During an Outage
During an Opensense outage, Microsoft 365 mail servers queue and retry mail delivery automatically. Opensense never handles the final delivery, so Microsoft’s retry logic prevents message loss.
Retry Mechanism: Microsoft 365 will automatically reattempt delivery until the Opensense service is reachable.
If retries fail after the maximum period, a Non-Delivery Report (NDR) or bounce-back will be sent to the sender, detailing the failure reason and suggested corrective actions.
Disable Signature Insertion from the Outlook Add-In
To prevent the Outlook Add-In from inserting or previewing signatures in email messages during an outage:
Log into the Opensense portal: https://accounts.opensense.com/
Navigate to: Manage → Domain Settings → Outlook Add-in (New UI)
For each domain:
Toggle OFF Automatic Signatures
Toggle OFF Plaintext Preview
These settings must be disabled per domain. Changes take affect immediately and prevent any client-side preview or insertion.
Disable Server-Side Stamping (Fallback Mechanism)
If the Outlook Add-In is inactive, Opensense can still apply the plaintext block via mail flow rules in Microsoft 365. To fully disable this fallback mechanism:
An O365 Admin must sign in to the Exchange Admin Center.
Navigate to Mail Flow → Rules.
Locate the rule named Opensense Stamping and disable it.
Disabling this rule halts all backend stamping processes, ensuring no server-side signatures are applied during downtime
Summary of Actions
Objective | Action |
|---|---|
Stop Outlook Add-In signature insertion | Disable Automatic Signatures and Plaintext Preview per domain |
Disable fallback server-side Stamping | Disable the Opensense Stamping rule in O365 Admin Center |
Resume full functionality | Re-enable Add-In settings and the Stamping rule when the outage is resolved |
Conclusion
Opensense’s architecture provides resilient and redundant email processing with minimal downtime. If you experience an outage, temporarily disabling the Outlook Add-In and/or the Stamping transport rule ensures that messages are delivered while systems recovers.
Opensense Support
For further assistance, contact Opensense Support:
Email: help@opensense.com
Knowledge Base: help.opensense.com