[CentOS] sendmail security

John Hinton webmaster at ew3d.com
Wed Sep 20 16:21:33 UTC 2006

Les Mikesell wrote:
> On Wed, 2006-09-20 at 05:12, abhishek singh wrote:
>> 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
>> like
>> mail from: <abs at domain.com>
>> this command is showing Sender is ok while its not
>> user in my mail server.after that 
> The stock Centos configuration should reject everything
> that doesn't come from the localhost unless you make
> changes to /etc/mail/access to permit it.  Are you
> doing this test from the local host?
Do you have telnet open to the outside world? If so kill it and only 
allow ssh with the proper extra security setup. You may need to open 
telnet for a little while for testing purposes, but don't leave it that way.

John Hinton

More information about the CentOS mailing list