[CentOS] sendmail security

Wed Sep 20 12:14:56 UTC 2006
Alexander Dalloz <ad+lists at uni-x.org>

abhishek singh schrieb:

Do not top-post please.

>yes i am using SMTP Authentication , but when i m
>doing telnet to my server on 25 port so i am able to
>send mail by unknow user that in in not my mail server
>mail from: <abs at domain.com>
The syntax isn't correct: there has to be no space in between

MAIL FROM:<abs at domain.com>

>this command is showing Sender is ok while its not
>user in my mail server.after that 
>rcpt to: <xyz at domain.com>
>after this mail is queued for delivery to xyz user and
>in this scenario xyz is valid user accound on my mail
>server so i want that unkown account for my domain
>cant sendmail , so how i will do that ,
>when i am sending mail to out side domain without
>authentication then everything is ok means any one can
>send mail to my domain while he is not user.
That makes no sense.

>this is the problem.
I do not see "the problem" from above statement. Just understand your 
question about avoiding to receive mail from faked senders (see below).

> i have one solution , but i want to know very easy
>way to do that