Thanks very much for your replies guys. The problem was actually something else, much more conventional (an old NAT rule forgotten, a public IP migration, and old IP range DNS records expiring). So the problem was on my side, they were only checking reverse lookup...
A document they sent me made me thought of what I posted. Sorry for bothering, and thanks! Vincent > -----Original Message----- > From: Jeremy T. Bouse [mailto:[EMAIL PROTECTED]] > Sent: Wednesday 18 December 2002 17:35 > To: [EMAIL PROTECTED] > Subject: Re: SMTP standards : needs outgoing SMTP server be MX for my > domain? > > > This could be an internal policy decision on their part... In > which case I would assume that the proper response back would be an > x.7.1 which states it's policy... Either 4.7.1 if it's not fatal or > 5.7.1 if it is... > > There is nothing that I am aware of that stipulates what an MTA > administrator can and can not set as internal policy for mail they are > willing to receive... In fact I'm in the process of designing > a Sendmail > milter for our network at work to enforce the policies we're putting > into place... One idea for it is to actually lookup the MX server for > the incoming domain and very the FROM address really is > valid... Now if > everyone accepted VRFY this would be easy but is not the case > thanks to > spammers which have caused many MTA admins to turn that > feature off... > > Another simple way to catch many spammers is to actually check > the HELO arguments and either later reject the message or just discard > it if the argument is not either 1) a valid FQDN, 2) domain name or 3) > IP address in proper notation... I've found many spammers just sending > random characters, as well as yahoo.com, hotmail.com, etc are popular > and even a few give my MTA my MTA's own IP address... > > Internal policy is internal policy and you can't really twist > their hand to change it... > > Jeremy > > On Wed, Dec 18, 2002 at 04:08:59PM +0100, DEFFONTAINES Vincent wrote: > > An organization refuses emails from my domain, under this reason : > > My domain's mailer that connects to their SMTP server is > not MX of my > > domain. > > > > Indeed it is not, I have different hosts for ingoing and > outgoing email > > traffic. > > Actually, I see no good reason why outgoing mailer should > be the same as MX. > > > > I am wondering if SMTP standards require that email sender > of a domain be > > its MX? I find that really surprising. > > > > I'll be glad to know if anyone can enlight me. > > > > Thanks, > > > > Vincent > > > > > > -- > > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > > with a subject of "unsubscribe". Trouble? Contact > [EMAIL PROTECTED] > > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact > [EMAIL PROTECTED] > -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
