HELP! My mail server is relaying for a spammer big time....

[JerryC at world.std.com (Jerry A Clabaugh)]

I also don't understand sendmail commands, but succeeded in shutting
down most relay methods by putting the following at the bottom of
my sendmail.cf file (I found this at
http://www.sendmail.org/~ca/email/check.html#check_rcpt)
I'm using sendmail 8.8.8


Scheck_rcpt
# anything terminating locally is ok
R< $+ @ $=w >		$@ OK
R< $+ @ $=R >		$@ OK

# anything originating locally is ok
R$*			$: $(dequote "" $&{client_name} $)
R$=w			$@ OK
R$=R			$@ OK
R$@			$@ OK

# anything else is bogus
R$*			$#error $: "550 relaying not allowed"



On Mon, 8 May 2000, Phil Buckley wrote:

> Help!
> 
> Being only the de facto sys admin, and having only a basic understanding of sendmail, I am now under seige from the spammers. Can some kind soul please help me shut my smtp door that I apparenly left not only unlocked, but wide open....
> 
> sendmail.mc file below::::::::
> 
> divert(-1)
> dnl This is the macro config file used to generate the /etc/sendmail.cf
> dnl file. If you modify thei file you will have to regenerate the
> dnl /etc/sendmail.cf by running this macro config through the m4
> dnl preprocessor:
> dnl
> dnl        m4 /etc/sendmail.mc > /etc/sendmail.cf
> dnl
> dnl You will need to have the sendmail-cf package installed for this to
> dnl work.
> include(`/usr/lib/sendmail-cf/m4/cf.m4')
> define(`confDEF_USER_ID',``8:12'')
> OSTYPE(`linux')
> undefine(`UUCP_RELAY')
> undefine(`BITNET_RELAY')
> define(`confAUTO_REBUILD')
> define(`confTO_CONNECT', `1m')
> define(`confTRY_NULL_MX_LIST',true)
> define(`confDONT_PROBE_INTERFACES',true)
> define(`PROCMAIL_MAILER_PATH',`/usr/bin/procmail')
> FEATURE(`smrsh',`/usr/sbin/smrsh')
> FEATURE(mailertable)
> FEATURE(`virtusertable',`hash -o /etc/mail/virtusertable')
> FEATURE(redirect)
> FEATURE(always_add_domain)
> FEATURE(use_cw_file)
> FEATURE(local_procmail)
> MAILER(procmail)
> MAILER(smtp)
> FEATURE(`access_db')
> FEATURE(`rbl')
> FEATURE(`blacklist_recipients')
> dnl We strongly recommend to comment this one out if you want to protect
> dnl yourself from spam. However, the laptop and users on computers that do
> dnl not hav 24x7 DNS do need this.
> dnl FEATURE(`accept_unresolvable_domains')
> FEATURE(`relay_hosts_only')
> dnl FEATURE(`relay_based_on_MX')
> 
> Phil Buckley
> 
> 
> -
> Subcription/unsubscription/info requests: send e-mail with
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> message body to discuss-request at blu.org (Subject line is ignored).
> 

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