parameter on a Microsoft Exchange Server 2007 server to exclude domain names from the Sender ID filter. In this situation, this setting may not take effect if the senders' domain names include capital characters. For example, you run the following command in Exchange Management Shell:
Set-SenderIDConfig -BypassedSenderDomains "contoso.com" -SpoofedDomainAction Reject
@contoso.com, the message is delivered without the Sender ID filter. However, if the sender is
@Contoso.com, the message passes through the Sender ID filter and may be rejected.