On 04/16/2015 03:45 AM, Per Jessen wrote:
antonaylward.com -> 66.33.210.248 As your domain has MX records, nobody is going to look at that entry in a context of mail delivery. Only if "antonaylward.com" had no MX records, would the MTA default to looking at that IP (as a potential mailserver).
I think you are making - a quite reasonable but unsupportable - assumption there. Its that all MTAs will act the way you think they should. One strategy is this: FIRST: If a site has an A record try delivering there. If there is no SMTP)s_ port of is the exchaneg fails then ... NEXT: If a site has a MX record then deliver to the MX address and let them worry about it. Hopefully is has a SMTP9s) port and is configured to store and forward --------- OR -------- Start with the MX site. So which do you think is the correct approach? I was brought up to the first, perhaps on the basis that some sites were poorly configued at the DNS level and didn't have or display MX. But this was back in the days of "open smtp" where it didn't matter, you could punt your email to any site (preferbaly on the backbone) and it would store-and-forward and, eventually, mail would get to its desired destination. Now we no longer have, thank you malicious agents, an open relay service :-( Back in those days of old it was considered good practice to have your name servers geographically dispersed. The root name servers are. Differnt techtonic plates. Diferent electrical grids. Differnt backbone providers. Can you say "resiliance"? Now we have this: ;; AUTHORITY SECTION: rogers.com. 799 IN NS ns3.wlfdle.rnc.net.cable.rogers.com. rogers.com. 799 IN NS ns2.ym.rnc.net.cable.rogers.com. rogers.com. 799 IN NS ns2.wlfdle.rnc.net.cable.rogers.com. rogers.com. 799 IN NS ns3.ym.rnc.net.cable.rogers.com. Those are on just 2 subnets 64.71.246.x 24.153.22.x They both hang off the same sub-branch! What's the logic here? Some years ago I dealt with a ISP in downtown Toronto. They had little to no UPS/DR capability. Their reasoning was that is they went down does to a power failure then so did all their clients since they were in the same building or the same city block/power-feed. You can see the failure in reasoning here? I think Rogers have a similar line of reasoning; if their backbone goes down so does that of all their clients. So its not an issue. But what of outsiders trying to send mail to rogers or rogers' clients such as myself? Personally I don't think the "try MX first" is a good strategy. Hmm. I should look up the RFCs and also see what Cricket has to say about it. -- A: Yes. > Q: Are you sure? >> A: Because it reverses the logical flow of conversation. >>> Q: Why is top posting frowned upon? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org