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In Mac Outlook, OnMessageAttachmentsChanged is not triggering for attachment additions. Removals still trigger, and from what I can tell in other platforms this is still working appropriately.

Your Environment

• Platform [PC desktop, Mac, iOS, Office on the web]: Mac
• Host [Excel, Word, PowerPoint, etc.]: Outlook
• Office version number: 16.104 (25121423)
• Operating System: Sequioa Version 15.7.3 (24G419)

Expected behavior

When you add an attachment to an email in Mac Outlook, the OnMessageAttachmentsChanged event fires appropriately.

Current behavior

When you add an attachment to an email in Mac Outlook, the OnMessageAttachmentsChanged is not triggering.

Steps to reproduce

1. Have an Add-in that listens for the OnMessageAttachmentsChanged launch event
2. Add an attachment l in Outlook Mac
3. Note that the event does not trigger by inspecting runtime logs

Context

We rely on this launch event to extract and analyse attachments and it not triggering is breaking security protection for our customers.

Useful logs

• Console errors
• Screenshots
• Test file (if only happens on a particular file)

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