Good morning
We are having a problem in that we are receiving a lot of spam to externally available distribution groups (ones that accept email from the internet as well as from within my organisation).
After viewing headers on mail received by a user who is a member of one of these distribution groups we see that there is no'X-MS-Exchange-Organization-SCL' header.
Does this mean that Exchange is not performing spam checking on emails sent to distribution groups? If this is the case is there anyway of turning this on?
This TechNet question seems to suggest this is the case, but in their situation they are using Forefront, we are not: http://social.technet.microsoft.com/Forums/en-US/467d092e-35e0-47ab-873e-2ce34aa6db0c/content-filter-and-distribution-groups-receiving-external-senders?forum=exchange2010
Any help or advice would be greatly appreciated.
Kind regards