Test: An IPv6 enabled mail system
Problem - e-mail rejected. Reason:
550 5.4.3 DNS reverse lookup failed. (IPv6:2001:470:0:aa::1e)
I run a strict anti-spam system, and that includes that hosts sending mail to me must be properly configured with a reverse DNS lookup that does not indicate a dial-up or dynamic assignment (and no reverse lookup also fails). This failure has nothing to do with MY IPv6 setup.
Whoops, thanks for pointing that out. rDNS should be pushed out shortly.
Thank you. However, as your "minimum TTL" field from your SOA record says 1 day, I'll have to check again tomorrow - for it will take that long for the "nxdomain" cached answer to time out.
The NXDOMAIN response should not be cached for that long, most servers that actually cache that response usually expire it after 2 hours.
Next problem. I now see the reverse entry, but it doesn't map back to a corresponding forward entry.
My error message: 550 5.4.8 DNS PTR mismatch. (IPv6:2001:470:0:aa::1e)
!dig -x 2001:470:0:aa::1e
...
;; QUESTION SECTION:
;e.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.a.a.0.0.0.0.0.0.0.7.4.0.1.0.0.2.ip6.arpa. IN PTR
;; ANSWER SECTION:
e.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.a.a.0.0.0.0.0.0.0.7.4.0.1.0.0.2.ip6.arpa. 210 IN PTR arc.he.net.
However, the forward lookup maps to a different address:
;; QUESTION SECTION:
;arc.he.net. IN AAAA
;; ANSWER SECTION:
arc.he.net. 2946 IN AAAA 2001:470:0:aa::2
"2001:470:0:aa::2" not included in "2001:470:0:aa::1e" - so mail still rejected by my anti-spam system. :o
Actually it's kinda odd that arc.he.net had extra ipv6 addresses configured on it out of the "aa" range. We've fixed this, and should only have 2001:470:0:aa::2 from that range now.
OK. It works now - at least for my system, so perhaps for others too (if they also have similar strict rules).
We also fixed it so if you simply don't have an MX entry in DNS, it should default to the provided site's AAAA record.
I was trying to do the email test today and got an error from qmail in my logs when the message was delivered.
SMTP Response: 451 See http://pobox.com/~djb/docs/smtplf.html.
Quote from: tatsuling on September 17, 2008, 03:27:12 PM
I was trying to do the email test today and got an error from qmail in my logs when the message was delivered.
SMTP Response: 451 See http://pobox.com/~djb/docs/smtplf.html.
I'll have to set up qmail somewhere to test, however we do send \r\n (<CRLF>) after every command sent.