Last thursday we learned about an issue introduced with the latest Microsoft Patchday for Microsoft Office 2013, or more specifically KB3172519 (). The patch provided through KB3172519 is an unusual one and unfortunately our current approach to restore functionality by adapting the Zarafa compat package, does not seem to provide a way to influence this new behaviour of Outlook. We are still investigating.
The current workaround is to remove this specific update from the workstation to restore the reply-all functionality.
For msi installations:
remove KB3172519
For C2R installations:
revert back to version 15.0.4911.1002 as described here:
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