From mboxrd@z Thu Jan 1 00:00:00 1970 Mime-Version: 1.0 (Apple Message framework v752.3) In-Reply-To: <98676E7E-775A-411A-B018-A3D238379E57@ar.aichi-u.ac.jp> References: <98676E7E-775A-411A-B018-A3D238379E57@ar.aichi-u.ac.jp> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <61172513-6773-4AA3-8EF0-182BD91D948B@mac.com> Content-Transfer-Encoding: 7bit From: Pietro Gagliardi Subject: Re: [9fans] detecting spam Date: Fri, 26 Oct 2007 23:16:20 -0400 To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Topicbox-Message-UUID: db330a20-ead2-11e9-9d60-3106f5b1d025 And you are using the standard Plan 9 mail system, I presume? I don't, since I don't have an internet connection to Plan 9 at the moment (my emails are sent via Mac OS X). A few days with Plan 9 and I've seen other security problems not related to email: 1) rc: the value of $path is (. /bin). It is a classic case not to have . as the first directory when searching for programs - it allows Trojan horses to form. 2) auth server: why do we need one for passwords anyways if we run on a desktop computer? I don't know how to set one up, but I'd just like to set a password without an error spitting back at me when I type "passwd". On Oct 26, 2007, at 10:51 PM, arisawa@ar.aichi-u.ac.jp wrote: > Hello, > > I receive many SPAMS everyday. > Most of them are from IP based dynamic FQDN. > Therefore detecting SPAM from FQDN is effective. > Almost all mails from IP based dynamic FQDN are SPAM. > However there are few important exceptions: > we have needs to send mails to users of our smtp host from > somewhere using DHCP. > > Plan 9 smtp server supports SMTP-AUTH so that legitimate users are > allowed to transfer their mails to other smtp server. > > We can also send mails to users of our smtp host using SMTP-AUTH. > However the information(the fact the mail is authenticated) is > discarded in delivering mails to mbox. Therefore these mails are > confused with SPAM. > > I think it is worthwhile to put a tag something like: > X-Authenticated-User: alice > following "Received: from ..." > in case that the mail is authenticated by alice. > > Kenji Arisawa >