Bonjour,
 
Voilà après avoir effectué un "DNS report" sur dnsstuff.com, j'obtiens plusieurs "Warnings" que je ne saisie pas très bien   .
Deplus j'ai quelques soucis d'envoi de mail par moment, en gros j'ai des avis de non distributions me disant qu'il n'arrive pas à contacter l'hote distant, en voici un exemple :
 
Impossible de contacter le(s) destinataire(s) suivant(s) :
 
      xxxxxxxx@xxx-xxxxx.fr le 19/12/2006 16:12
            Vous n'êtes pas autorisé à envoyer de message à ce destinataire. Pour obtenir une assistance, contactez votre administrateur système.
            < mailsrelay.xxxxxxx.fr #5.7.1 smtp; 550 5.7.1 <xxxxxxx@xxx-xxxx.fr>... Relaying denied. Proper authentication    required.>
 
 
Et voici les Warning que j'obtient en faisant un DNS report sur mon domaine xxxxxx.fr:
 

Nameservers on separate class C's :
WARNING: All of your nameservers (listed at the parent nameservers) are in the same Class C (technically, /24) address space, which means that they are probably at the same physical location. Your nameservers should be at geographically dispersed locations. You should not have all of your nameservers at the same location. RFC2182 3.1 goes into more detail about secondary nameserver location.
 
Mail server host name in greeting :
WARNING: One or more of your mailservers is claiming to be a host other than what it really is (the SMTP greeting should be a 3-digit code, followed by a space or a dash, then the host name). If your mailserver sends out E-mail using this domain in its EHLO or HELO, your E-mail might get blocked by anti-spam software. This is also a technical violation of RFC821 4.3 (and RFC2821 4.3.1). Note that the hostname given in the SMTP greeting should have an A record pointing back to the same server. Note that this one test may use a cached DNS record
 
SPF record :
Your domain does not have an SPF record. This means that spammers can easily send out E-mail that looks like it came from your domain, which can make your domain look bad (if the recipient thinks you really sent it), and can cost you money (when people complain to you, rather than the spammer). You may want to add an SPF record ASAP, as 01 Oct 2004 was the target date for domains to have SPF records in place (Hotmail, for example, started checking SPF records on 01 Oct 2004).
 
 
Pourriez vous m'eclaicir sur ces Warnings, merci.