Hi @michael lustig ,
"Changes made to the item were lost due to a reconnect with the server."
Under what circumstances does this error usually occur(when the user creates a new message or others)? And could the issue be reproduced on his web mail?
If it occurred on Outlook only, it may be related to Outlook client. What's the version of your Outlook 2016(File>Office account>About Outlook), please first ensure that you have updated to the latest version of Outlook client.
Also, please understand here we mainly focus on general issues about Outlook desktop client and know little about citrix, I would provide some suggestions on this error from the perspective of Outlook client.
- According to my experience, due to any third-party add-ins or programs may cause Outlook disconnect to server, which may cause the error, it's recommended to close other programs and restart Outlook in safe mode to check(Windows+R> type"outlook.exe /safe">enter).
- If the issue still exists, considering it may also cuased by corrupted Outlook profile, please try to create a new Outlook profile and readd your account for testing(control panel>>Mail>show profiles>add>readd your account)
If that's invalid, please provide us with more information about your issue(such as Mailbox server type, whether the issue occurred on specific mailbox on the specific client only etc.)
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