It appears there are tons of emails trying to be sent out from our system. I opened up these emails and some have a from address of firstname.lastname@example.org and other from field is black.
This appears to be a NDR attack. Now I know somewhat about the filtering options but we have windows 2000 and it was not suggested to apply any filtering because of AD harvest issues.
Since we do not have windows 2003 to turn on tar pitting option what can I do? This is causing all kinds of bouncebacks to employees trying to say they sent an email to ex-employees that no longer exist.
Our queues are really starting to fill up quickly after I cleared them.