Question about Internal spam

[Rob Sterenborg]

> Hello,
> 
> I would like to know why the mail  users  (server:
> centOS+sendmail+mailscanner) are receiving mails from their
> own address
> i,e:
> 
> mail from: user1 at domain.com
> mail to: user1 at domain.com
> subject: stock options....

Do the "Received: " headers of the emails tell you that the email
originates from the internet instead of your LAN?

> Also I would like to know if you have any recomendation in order ot
> avoid this? 

If this email comes from the internet, don't accept email (from the
internet) that has your domain in the sender email address. IMO, if
*your* MTA is the only one on the internet that sends email for *your*
domein, you can do this. If there are other mailserver that send email
for your domein, you might/will lose email doing this and you must think
of another solution.
Since I don't use Sendmail, I can't help you there.


Grts,
Rob