[CentOS] sendmail security-with example

[Feizhou]

Mahayudin Mohd Hashim wrote:
> abhishek singh wrote:
>> i have never opened telnet ok , my xinetd service is
>> off so there is no telnet service , i m doing telnet
>> to outside to 25 port on my mail server and there is
>> proper smtp authentication  enabled on server , the
>> problem is anyuser (non-existing) with my domain can
>> send mail to my real domain users.
>> below is example........
>>   
> 
> Check this and do accordingly ...
> 
> http://www.sendmail.org/faq/section3.html#3.27
> http://www.sendmail.org/tips/relaying.html
> 
> hope this help!
> 

It does not. He does not have a relay problem. He wants to reject mails 
that have sender addresses claiming to be from his domain and not only 
that, they are also forged (non-existent).