2006年10月10日 下午 04:13
In the last couple of days we have been receiving hundreds of bounceback emails that were sent by spammers using our domain.
How can I put a stop to it?
2006年10月11日 上午 05:51
Dont accept mail from your domain on the SMTP server that receives mail from Internet.
2006年10月13日 下午 08:56
This is a good recommendation that will prevent spam that spoofed the sender sent directly to jBarrik's org.
But the problem reported is that spam campaigns went to a large list of recipients in different domains, pretendeing to originate from jBarrik's domain. The domains targetted rejected the email (spam filters or just invalid recipient or mailbox full, etc) and these NDRs returned to jBarrik.
(a good reminder for all of us to not configure the hygiene filters to generate NDRs, especially for unauthenticated users.)
Anti-spam solutions should be able to help in this case, although the format of the NDRs will differer based on the domain that bounced it.
Another important thing to consider is publishing the SenderID record for your domain. this requires no changes to the email infrastructure but only adding data to the existing DNS record for the domain. Net result is that other orgs can detect messages that are spoofed as originating from your domain and can drop them without sending a delivery status notification (DSN/NDR) http://www.microsoft.com/senderId
Most spam filters also include keyword filtering and finding a good set of keywords that cover specific spam campaigns and filtering message that include those in their subject can be a good idea.