Educause Security Discussion mailing list archives
Re: smtp redirection
From: Valdis Kletnieks <Valdis.Kletnieks () VT EDU>
Date: Tue, 10 May 2005 15:57:17 -0400
On Tue, 10 May 2005 14:32:09 CDT, John said:
We are redirecting smtp traffic inbound to some campus mail servers via MX records in our DNS to an anti-spam appliance (Bluecat Meridius) and find some email circumvents the appliance apparently by using DNS IP lookup for host resolution and not using MX records to send mail to mail servers on our campus. The vendor recommends blocking inbound port 25 to the campus mail servers from the internet. I favor this approach. However the mail folks are concerned that some legitimate email may be dropped this way.
It's been *many* moons since anything except ratware failed to do MX handling in some reasonable manner. I mean, come *ON*, MX records were defined in RFC973. Back in January 1986. If your mail folks can identify a system *still* on the Internet that's running software *so* old that it can't do MX, please let me know - as far as I know, all systems that stored 6 6bit, 5 7-bit, or 4 9-bit characters in a 36-bit word had long since boarded the Elven ships at the Grey Havens and passed into the West, taking their magic and mystery with them. ********** Participation and subscription information for this EDUCAUSE Discussion Group discussion list can be found at http://www.educause.edu/groups/.
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Current thread:
- smtp redirection John (May 10)
- <Possible follow-ups>
- Re: smtp redirection Aaron Childs (May 10)
- Re: smtp redirection Flagg, Martin D. (May 10)
- Re: smtp redirection Graham Toal (May 10)
- Re: smtp redirection Graham Toal (May 10)
- Re: smtp redirection Geoff (May 10)
- Re: smtp redirection Valdis Kletnieks (May 10)
- Re: smtp redirection Valdis Kletnieks (May 10)
- Re: smtp redirection Bruce Hudson (May 10)
- Re: smtp redirection Tom Bossie (May 10)
- Re: smtp redirection Flagg, Martin D. (May 10)
- Re: smtp redirection Graham Toal (May 10)
- Re: smtp redirection Paul Russell (May 10)
- Re: smtp redirection Valdis Kletnieks (May 10)
- Re: smtp redirection Mark Borrie (May 10)
- Re: smtp redirection Valdis Kletnieks (May 10)
- Re: smtp redirection John (May 10)
(Thread continues...)