Open Relay

[jpmigue]

I am running sendmail 8.11.2 on a redhat system. The system runs as an open relay and has been blacklisted. It is documented that the system had a buggy linuxconf that means it is susceptible to the trailing @ hack. I cannot find a compatible more recent linuxconf and have therefore tried the following but the percent hack still gets through:

Recompiled sendmail.cf using m4
Manually edited sendmail.cf and inserted documented check_rcpt rules.
Inserted the documented check_rcpt rules into a newly compiled sendmail.cf
I thought this version of sendmail barred relaying mails by default!

Any assistance greatfully received

James

 

[rouse01]

James,
I used to use linuxconf but I read that it had some major problems & it wasn't being supported anymore. Try using webmin instead, which can be used to configure your linux server - including sendmail.
On the relay problem, check out these links. I believe there is something wrong with your /etc/mail/access & /etc/mail/relay-domains:

http://www.experts-exchange.com/Networking/Linux_Networking/Q_11001401.html

http://www.utexas.edu/cc/unix/mail/closing-relay.html

Hope this helps,
Keith

 

[Rhinokiller]

Never use linuxconf to configure sendmail it's broken.
check your sendmail.mc for the following
FEATURE(`RELAY_ENTIRE_DOMAIN')
if it is there remove it as this allows relaying for entire class m
You will also have to configure your box to relay domain literal to be removed from some DSBL lists (RFC 1122 /1123 methinks).

There is no God, only 10001010

 

[jpmigue]

I know linuxconf is broken, it is the reason that my box relays. The .mc file I am testing has only the followig entries:

OSTYPE(`linux')
DOMAIN(`generic')
FEATURE(`nouucp', `reject')
MAILER(`local')
MAILER(`smtp')


The system as a rule does not relay but always falls foul of the trailing @ in a rcpt address. Every piece of documentation I come across tells me what I know - it is the check_rcpt rule that should be catching this - but I still cannot fix the trailing @ hack.

Cheers

James