nanog mailing list archives
Re: SMTP addresses in <>
From: Joe Greco <jgreco () ns sol net>
Date: Fri, 4 Jan 2008 10:27:47 -0600 (CST)
On Jan 4, 2008 10:51 AM, Seth Mattinen <sethm () rollernet us> wrote:Our mail servers reject connections that don't follow the RFC. Am I wrong to do this?Seth, RFC 1122 (Requirements for Internet Hosts - Communication Layers) section 1.2.2 (Robustness Principle): "Be liberal in what you accept, and
That particular philosophy has done great wonders for e-mail and the spam problem, been a key issue on both the penetration and implementation sides of firewall design, etc. "Liberal," when defined as "accept anything you reasonably can, and try to deal with it," appears to be a policy that has had an overall negative impact on protocol design and interoperability on the Internet. "Liberal," if defined instead as "must accept anything in compliance with RFC sender-side MUST/SHOULD/MAY's, and should reject as much of anything else as you can figure out to," would be a better way to have defined "liberal." I think I would have preferred the word "robust" instead of "liberal." This would have spared us the agony of systems that are "smart" enough to go direct-to-MX, but not smart enough to send a valid FROM line.
conservative in what you send"
If only a more significant percentage of software was written in that manner... ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.
Current thread:
- SMTP addresses in <> Seth Mattinen (Jan 04)
- Re: SMTP addresses in <> William Herrin (Jan 04)
- Re: SMTP addresses in <> Donald Stahl (Jan 04)
- Re: SMTP addresses in <> Sean Donelan (Jan 04)
- Re: SMTP addresses in <> Randy Bush (Jan 04)
- Re: SMTP addresses in <> Donald Stahl (Jan 04)
- Re: SMTP addresses in <> Joe Greco (Jan 04)
- Re: SMTP addresses in <> William Herrin (Jan 04)
- Re: SMTP addresses in <> Joe Greco (Jan 07)
- Re: SMTP addresses in <> Andrew Sullivan (Jan 04)
- Re: SMTP addresses in <> Alexander Harrowell (Jan 04)
- Re: SMTP addresses in <> Sean Figgins (Jan 04)
- Re: SMTP addresses in <> Greg Skinner (Jan 04)
- Re: SMTP addresses in <> William Herrin (Jan 04)
- [admin] Re: SMTP addresses in <> Martin Hannigan (Jan 04)
- Re: SMTP addresses in <> Randy Bush (Jan 04)
- Re: SMTP addresses in <> Valdis . Kletnieks (Jan 04)
- Re: SMTP addresses in <> Jeff Kell (Jan 04)