Hi Audric,

> During the last few days I got hundreds of these:
> 
> Dec 12 09:04:08 qube3 sendmail[20950]: NOQUEUE: mrh.rcmail.com [216.54.1.19] did not 
>issue MAIL/EXPN/VRFY/ETRN during connection to MTA
> 
> should I worry.

Jepp. Could be that someone connected manually to your sendmail port and is/was trying 
to trick it into doing bad stuff. 

You can test it out by using "telnet <your.ip.address> 25". Sendmail will then greet 
you and expects to talk to a mail programm or other mail server. You can basically 
send emails that way by just typing the commands that Sendmail expects during a normal 
mail connection, or by letting a script generate them. 

The error message above (did not issue MAIL/EXPN/VRFY/ETRN) tells us that the 
connecting party got past the initial "HELO" greeting, but then didn't behave as 
sendmail expected.

> Meanwhile I changed the default rule of my firewall from accept
> to deny.

Sounds like a good idea. You could of course block this IP-address or the entire 
address range of the originating ISP instead.

-- 
With best regards,

Michael Stauber
SOLARSPEED.NET
_______________________________________________
cobalt-security mailing list
[EMAIL PROTECTED]
http://list.cobalt.com/mailman/listinfo/cobalt-security

Reply via email to