Incident Initiation:
Starting from 17th February, we slowly started to receive increasing reports from customers regarding an issue related to the slowness and inability to automatically insert email signatures through the Email Signature Outlook Web Add-in in Outlook Desktop, particularly in the Classic or Old version. As a result, an incident was formally created on February 19, 2025, at 10:21 AM CET. This issue disrupted the daily operations of multiple customers, preventing the proper functionality of the signature insertion feature.
Investigation:
The engineering team initiated an investigation into the issue. Initial analysis revealed that an upgrade to the Office JS version had been applied to the Classic or Old version of Outlook Desktop. This upgrade led to an increased number of exceptions, which sometimes resulted in slower signature insertion or, in some cases, prevented the insertion process from completing successfully. Since the exception is triggered by an external system (Office JS) to which we do not have direct access, further root cause analysis and resolution are limited.
Mitigation and Resolution:
To mitigate the impact of the issue, a workaround was provided to affected customers on February 19, 2025, at 04:48 PM CET. The workaround recommended switching to the New Outlook or Outlook Online, which resolved the problem. Additionally, to further assist with support and troubleshooting, a dedicated guide for using the Email Signature Web Add-in in the Classic version of Outlook Desktop was created.
Given that the issue originates from an external system, we are unable to fully prevent its occurrence. The product's functionality remains dependent on the external Office JS system.
Impact and Scope:
The incident affected multiple customers, only those using the Classic or Old version of Outlook. Users experienced delays in signature insertion or the failure of signature insertion altogether. This issue impacted a significant number of users across all production environments.
Post-Incident Actions:
Moving forward, we will be investigating on how we can collaborate more closely with Microsoft’s Outlook or Office JS teams to expedite the identification of the root cause.
We sincerely apologize for the disruption caused by this incident and want to reassure our customers that we remain committed to providing reliable and stable services. Our team will continue to monitor the situation and explore ways to prevent similar issues in the future.