Hi @Jayakumar Janardhanan ,
You could following the steps to delete the recurring meetings. Please pay attention to the following things before running the commands: By default, Search-Mailbox is available only in the Mailbox Search or Mailbox Import Export roles, and these roles aren't assigned to any role groups.You need to add both of the roles to a role group.Only the Mailbox Import Export role gives you access to the DeleteContent parameter. And run the Search-Mailbox each mailbox returns up to 10,000 results each time.
1.Please run the following command in the Exchange Management shell to preview eligible results:
Get-Mailbox -ResultSize Unlimited | Search-Mailbox -SearchQuery "kind:meetings AND Subject:'<Meeting subject>' AND From:<>" –EstimateResultOnly
2.Then run the following command in the Exchange Management shell to delete all eligible meeting series from both the organizer mailbox and the attendees mailbox:
Get-Mailbox -ResultSize Unlimited | Search-Mailbox -SearchQuery "kind:meetings AND Subject:'<Meeting subject>' AND From:<>" -DeleteContent
For more information you could refer to: Search-Mailbox
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