nanog mailing list archives
Re: Is Hotmail in the habit of ignoring MX records?
From: Mark Andrews <marka () isc org>
Date: Fri, 27 Jul 2012 12:45:37 +1000
In message <B59A4092-CE2F-44E4-84F9-77C18493AD95 () kapu net>, Michael J Wise writ es:
On Jul 26, 2012, at 6:34 PM, Mark Andrews wrote:In message <A9A5C64B-831D-42BF-8A38-56CC3B9BAF48 () kapu net>, Michael J =Wise writes:=20 On Jul 26, 2012, at 1:35 AM, Lou Katz wrote: =20The domain is cookephoto.com=20 Why does mail.metron.com have MX records?=20 Why do you care? There is nothing wrong with having explict MX records and they generally take up less room in a DNS cache then the negative response does especially if it is DNSSEC signed. =20And they're different.=20 Again why do you care?Why do *I* care? I don't. I'm just trying to find the weird bit that maybe is causing hotmail to = stumble. And maybe an endless loop for an MX lookup might be what is causing = hotmail to panic and throw out the MX records.
You don't lookup MX records for MX targets. This is basic MTA processing. If the MX lookup fails, as apposed to returns nodata, you don't lookup the A/AAAA records and synthesis a MX record. You treat it as a soft error and queue for retry later. Again this is basic MTA processing. You don't depend on ALL (ANY) returning MX records as they may not be in the cache. You need to make a explict MX query you get no MX records are returned in response to a ALL query. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka () isc org
Current thread:
- Re: Is Hotmail in the habit of ignoring MX records?, (continued)
- Re: Is Hotmail in the habit of ignoring MX records? David Miller (Jul 27)
- Re: Is Hotmail in the habit of ignoring MX records? Michael J Wise (Jul 27)
- Re: Is Hotmail in the habit of ignoring MX records? Mark Andrews (Jul 27)
- Re: Is Hotmail in the habit of ignoring MX records? Michael J Wise (Jul 27)
- Re: Is Hotmail in the habit of ignoring MX records? Lou Katz (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Mark Foster (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Michael J Wise (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Mark Andrews (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Michael J Wise (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Mark Andrews (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Scott Howard (Jul 27)
- Re: Is Hotmail in the habit of ignoring MX records? William Herrin (Jul 29)
- Re: Is Hotmail in the habit of ignoring MX records? Mark Andrews (Jul 30)
- Re: Is Hotmail in the habit of ignoring MX records? William Herrin (Jul 30)
- Re: Is Hotmail in the habit of ignoring MX records? valdis . kletnieks (Jul 30)
- Re: Is Hotmail in the habit of ignoring MX records? Jimmy Hess (Jul 30)
- RE: Is Hotmail in the habit of ignoring MX records? George Bonser (Jul 26)
- Re: Is Hotmail in the habit of ignoring MX records? Lou Katz (Jul 26)