Seeking for your inputs in this issue. Duplicating happens randomly right after deletion and there's no pattern
The issue only appeared in Outlook, while OWA is fine
Checked Outlook update
Created new Outlook profile
Uninstalled and reinstalled Office
Accessed the same email to different PC - same issue
Exported and Deleted items as PST
Emptied deleted folder in Outlook and OWA
Deleted all recoverable items in Outlook web app. Log in to Outlook Online > went to deleted folder > Recovered items deleted in this folder > emptied or delete them all. Performed this in OWA as well
Went to Registry and delete the profiles though this path HKEY_CURRENT_USER/Software/Microsoft/Office/16.0/Outlook/Profiles/profile-name
Completely uninstalled and reinstalled Office - Manually uninstall Office (microsoft.com)
Createed new Outlook profile again
Added the email in different PC -same issue
No rules found in Outlook & OWA
Ran MFCMAPI -didn’t find any rule
Ran these commands in PS
Install-Module -Name ExchangeOnlineManagement
Set-OrganizationConfig -ElcProcessingDisabled $false
Set-Mailbox "email" -RemoveDelayHoldApplied
Set-Mailbox "email" -RemoveDelayReleaseHoldApplied
Set-Mailbox "email" -ExcludeFromAllOrgHolds
Set-Mailbox "email" -ElcProcessingDisabled $false
Set-Mailbox "email" -SingleItemRecoveryEnabled $false
Start-ManagedFolderAssistant -Identity "email"
Right-click on the deleted folder >> clicked on Properties.
Clicked ‘Clear Offline Items’ option under the dialog box. hit Ok.
On Outlook ribbon, selected Send/Receive option.
Clicked Update Folder to save the changes.
Repaired Outlook Data Files
Navigated to C:\Users\<User>\AppData\Local\Microsoft then renamed Outlook folder
Ran MS Outlook in Safe Mode
Right click Windows icon select Run. Type outlook /safe
Tried to delete some emails -same issue
Disabled Anti-virus & Firewall settings
Tried other PC and/or new Windows profile
Created a new Outlook profile - using Sara Tool
Went into the Microsoft 365 Admin portal -> Users -> Active Users
Selected the user that is having the problem.
Selected the Mail tab.
Under Email apps, chose Managed email apps.
Deselected POP and IMAP
Saved the changes
Went back to the Account tab
Clicked sign out all sessions.
Issue still persist......