CmdID / PowerShell / Cmdlets / Remove
Remove-SafeAttachmentRule
Use the Remove-SafeAttachmentRule cmdlet to remove safe attachment rules from your cloud-based organization. Exchange PowerShell reference
From the Exchange PowerShell reference 3 parameters Its page in the reference
Parameters
-IdentityThe Identity parameter specifies the safe attachment rule that you want to remove.-Confirm, -cfThe Confirm switch specifies whether to show or hide the confirmation prompt.-WhatIf, -wiThe WhatIf switch shows what the command does without making any changes.