[CentOS] sendmail security-with example

[Feizhou]

abhishek singh wrote:
> i have solved one problem that was 1st example in my previous mail. 
> means now no unknow user from my domain can send mail to my real users 
> of mydomain but still there is 2nd problem means anyone can telnet to my 
> server and can forge real domain address to sendmail to my domain users 
> like

Tell you what. Just ditch the whole sendmail thing and use postfix. If 
you are not using virtuser table, there should be very little, if not 
zero, changes.

http://www.postfix.org/ADDRESS_VERIFICATION_README.html

Postfix can do both with a few config lines natively. Just take note 
that some people do not appreciate callback verification.