It seems that Windows 10 Pro v1903 suspends Microsoft Outlook (365 or 2019 with latest office build v1908) when remote desktop user disconnects session (user closes session and does not log off).
In summary, we use remote desktop to connect to a clean install Windows 10 v1903 VM with Microsoft Outlook installed (365 or 2019 with latest build 1908). We set Outlook to Offline mode, queue 10 emails, turn Outlook back to online and quickly disconnect the session (not logging user out). I would expect that the emails should be sent. This however does not happen and is only sent when I log back into the remote session.
We can confirm that:
- It is not a Windows 10 power and sleep setting, as all screen savers, sleep modes and such are disabled.
- It is not a ‘System unattended sleep timeout’ as set out in this post. Bear in mind that the ‘suspension’ is immediate and does not take effect after 1 or 2 minutes.
- It is not the NIC that is suspended, as we ran console ping tests while disconnected, which continued to poll.
- But most importantly, an exact duplicate of the setup, using a Windows 10 Pro v1809 build, does not suspend Outlook build 1908, and the queued emails is successfully sent.
- Updated. Changed group policy settings' Session Time Limits as suggested by harrymc, but it was unsuccessful.
- Updated. The Terminal Server registry fix suggested here by harrymc , did not resolve the problem.
- Workaround This disconnect shortcut proposed by harrymc DID WORK as interim workaround.
We are therefore convinced the problem is with a setting change on remote desktop users in Windows v1903. We have found that only Outlook is so far affected.
Any comment that might point us in the right direction to restore the functionality to Outlook whilst the remote session is disconnected, will be highly appreciated.