I've been trying to track down an issue where our mail server users are complaining of receiving emails from fake accounts that have their domain name associated with them. After looking through this further it appears to be spam and viruses that are coming through with headers that are from other sources but ours.
Were currently running fedora core yarrow release 1, with sendmail 8.12.10
After research I'm guessing I need to change the sendmail.mc to do header checks but I was wondering if I could configure the server to check against either the virtusertable or local accounts to see if that user sending mail is an actual account on this server.
Thanks in advance for any help.
I currently only have 40 points to offer but I will consider buying more if need be.
Also if any linux tech's are in the cleveland area my bosses may be interested in talking about further linux support help.