Task: Configure message throttling for your organization with recipient rate limit of 5000 and message rate limit of 20
Use this command:
New-ThrottlingPolicy -Name fightspam -RecipientRateLimit 5000 -MessageRateLimit 20
Now Apply policy to particular mailbox:
Set-Mailbox -Identity user_alias -ThrottlingPolicy fightspam
Use this command to apply to an Organizational Unit:
get-mailbox -OrganizationalUnit ‘domain/OU’ -resultsize unlimited | set-mailbox -Throttling
Policy fightspam