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reverse dns : the hostname given in the SMTP greeting must have an A record...

trucmuche
Hello, I have a NDD (gandi) and it uses the Gandi name servers to point to my vps. I wrote the gandi zone file for this domain and I asked my provider to configure the reverse dns (PTR). Everything works perfectly... except I got two warnings when I test the domain with dnsqueries.com. It says : 1) Your nameserver do not include A records when asked for your NS records. 2) The configuration of your mail servers and your DNS are not ok! The report of the test is: mydomain.com. -> www1.mydomain.com -> xx.yyy.zzz.ttt -> mydomain.com Spam recognition software and RFC821 4.3 (also RFC2821 4.3.1) state that the hostname given in the SMTP greeting MUST have an A record pointing back to the same server. Considering that the DNS server I use are the GANDI's one and not the VPS ones, what should I modify ? I don't understand if I have to modify something in WHM or in the zone file in Gandi configuration of my domain... Could you help me, please ? trucmuche

Comments

6 comments

Date Votes
  • LostNerd
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    • You need to create an "A" record for each of your nameservers.
      ns1.domain.com 14400 IN A 123.123.123.123 ns2.domain.com 14400 IN A 321.321.321.321
    • I believe this is because the reverse DNS does not exactly match the SMTP banner.
    0
  • cPanelMichael
    Hello, You will need to ensure an "A" record is configured for your server's hostname pointing back to the IP address of the server. Add the "A" record in the DNS zone of wherever the DNS for the domain name it's associated with is handled. Thank you.
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  • trucmuche
    1. Hmmmm. Thanks but it remains something unclear for me... I use the Gandi's DNS and here is the zone file that I use for my domain (xxx.yyy.zzz.ttt is the IP address of my vps) : * 10800 IN A xxx.yyy.zzz.ttt @ 10800 IN A xxx.yyy.zzz.ttt cpanel 10800 IN A xxx.yyy.zzz.ttt ftp 10800 IN A xxx.yyy.zzz.ttt mail 10800 IN A xxx.yyy.zzz.ttt webdisk 10800 IN A xxx.yyy.zzz.ttt webmail 10800 IN A xxx.yyy.zzz.ttt whm 10800 IN A xxx.yyy.zzz.ttt www 10800 IN A xxx.yyy.zzz.ttt www1 10800 IN A xxx.yyy.zzz.ttt Are you saying that I should add to my Gandi zone file the following : a.dns.gandi.net 14400 IN A 173.246.98.1 b.dns.gandi.net 14400 IN A 213.167.229.1 c.dns.gandi.net 14400 IN A 217.70.179.1 ??? 2. when I check my smtp server with mxtoolbox, it says : SMTP Valid Hostname : Reverse DNS is not a valid Hostname SMTP Reverse DNS Mismatch : OK - xxx.yyy.zzz.ttt resolves to mydomainname.com SMTP Banner Check : OK - Reverse DNS matches SMTP Banner SMTP TLS : OK - Supports TLS. SMTP Connection Time : 1.014 seconds - Good on Connection time SMTP Open Relay : OK - Not an open relay. SMTP Transaction Time : 3.463 seconds - Good on Transaction Time Thanks again... Trucmuche
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  • cPanelMichael
    One additional note to keep in mind is that often times you must have RDNS configured by your data center. You can request they configure RDNS for your IP address to point back to the hostname of your server. Thank you.
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  • trucmuche
    Yes, I already asked to my datacenter to configure the RDNS, it's done (and the warning I'm taking about is given after the propagation of the RDNS)... Could you tell me if the modification I have written in my precedent post is the thing I have to do ? Or am I misunderstanding something ? Thanks again...
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  • cPanelMichael
    Could you tell me if the modification I have written in my precedent post is the thing I have to do ? Or am I misunderstanding something ?

    Yes, you should add "A" records for your name server entries and your hostname at the DNS provider for the domain name associated with those records. Thank you.
    0

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