Is there a way we can block a single user from sending mail to any distributiongroups in our domain all at the same time?

Is this an internal or external user?

Hi, You can add that user to the Rejected Sender list of required Distribution Group in Exchange 2007. Regards,Laeeq Qazi|Snr Software Engineer(Exchange + Sharepoint + BES + DynamicsCRM) www.hostingcontroller.com

HI, I think you want to block a single user from sending emails to any distribution group in your domain am wrong please let me know.You can do it using transport rules. Please Fallow below procedure.1) Microsoft Exchange |Organization configuration | Hub Transport 2) Click New Transport rule on task paneThen new transport rule wizard appears3) Give the name for your rule then click next4) In the condition page select from people and select user you want to block sending emails to distribution, then select sent to a member of distribution list and select all distribution lists in yourorganization.Then action page appears5) Select saliently Drop message or any one you want then click next and click New to precede the command.More informationHow to use Transport Rules in Exchange Server 2007Overview of Transport RulesRegardsChinthaka

Use the Exchange Management Shell:Get-DistributionGroup | Set-DistributionGroup -RejectMessagesFrom <user> -WhatIfAfter verifying that this is what you want, remove the -WhatIf

Hi,Set-DistributionGrouphttp://technet.microsoft.com/en-us/library/bb124955.aspxThanksAllen