Sendmail Scanning/Errors????
Somebody is trying to send an email to a user on the server. Note, that this user does not actually exist. Its just some name.
I use POP before SMTP for security on the server. As a result, all of these attempts to relay mail fail. Also, many attempts fail because PTR errors, IP lookups, or non-existent domain errors.
At first, I thought a client had misconfigured thier email software, but the requests are comming from various domains and IP addresses. There have been about 100 various IPs used. Although some of these IP's reside in the same block, there are at least 10-15 different IP blocks represented.
Does anybody have any insight into what is going on here?
Is this some type of scan to look for possible relay holes on the server???
