Re: SMTP vulnerabilities

[David Correa <tech@xxxxxxxxxxxxxx>]

On Sat, 1 Dec 2001, [iso-8859-1] Jihène Krichène wrote:
> As you know, SMTP is vulnerable to DoS attacks (mail bombing and spamming).

To stop SPAM I use several things, they seem to work for me. Once in a
while i get some SPAM, but once they get in I check the email header and
block their mail server via iptables.

I also use tcpserver like this, not sure if this is the best way, but it
seems to work =>

/usr/local/bin/tcpserver -p -v \
-x/var/qmail/control/tcp.smtp.cdb -u<your UID>  -g<your GID> 0 smtp \
/usr/local/bin/rblsmtpd -r relays.osirusoft.com -r relays.ordb.org -r \
orbs.gst-group.co.uk  /var/qmail/bin/qmail-smtpd 2>&1 &

Some spamer are harder to get than others, because they have many mail
servers (i.e. many IPs). For these I use procmail to filter SPAM using the
doamin name of the mail server of the spammer.

::dc::

David Correa RHCE CCNA    _    _ _  _ _  _ _  _    ___ ____ ____ _  _
tech@linux-tech.com       |    | |\ | |  |  \/      |  |___ |    |__|
http://www.linux-tech.com |___ | | \| |__| _/\_     |  |___ |___ |  |


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