Title: Some users’ email with attachments sent from Outlook for Mac may be delivered without attachments
User impact: Users’ email with attachments sent from Outlook for Mac may be delivered without attachments.
More info: Users can verify if they’ve encountered this problem in Outlook for Mac by reviewing their Sent Items to validate if a sent message contains an attachment. If users don’t see the attachment, they can reply to the message in their Sent Items folder to reattach and send the message again.
Current status: We’ve implemented a fix and have seen a reduction in attachment removal errors by approximately 50 percent. We’re in the process of validating another fix which is expected to further reduce the number of observed errors. The deployment of the additional fix is expected to take some time and we’ll aim to provide a timeline to its deployment once feasible. In parallel, we’ll continue to monitor the affected environment to ensure that our remediation efforts are proceeding as expected and in a timely manner.
Scope of impact: This issue is specific to a very small percentage of users’ email with attachments sent from Outlook for Mac.
Start time: Monday, July 10, 2023, at 8:08 PM UTC
Root cause: A conflict occurring with how our service detects attachment IDs before sending email in Outlook for Mac is resulting in the service removing attachments on sending email.
Next update by: Tuesday, November 28, 2023, at 10:00 PM UTC
