--On 4 March 2008 15:45:08 +0000 Paulo Almeida <[EMAIL PROTECTED]> wrote:
>> Actually, the problem isn't solved, since the problem was with the >> recipient's callouts. They should be checking all your MX servers. They >> should not be hard failing on a temporary error. >> >> Who was the recipient? > > Hi Ian, > > We could not send any email to ua.pt domain. > In response to MAIL FROM for our mail server (MAIL FROM:<[EMAIL PROTECTED]> > for example), they refuse it with a 572 error: [EMAIL PROTECTED] host name > is unknown. > > But, if i telnet MAIL FROM:<[EMAIL PROTECTED]>, they accept the > message. In this case, recipient was [EMAIL PROTECTED] > > What i understand, is that they make some kind of host/sender verification > policy, by testing if the right part at '@' is a valid host. > esenf.pt is not a real host, but mail.esenf.pt is (our mail server). > > Tom Kistner advise me that maybe the reason was the our lowest priority MX > server point to a fake address (host mx0.esenf.pt not found: > 3(NXDOMAIN)). I remove that entry in dns and the messages start to be > accepted. > Like you say, i suppose too that they should checking all ours mx servers, > but apparently if they received a failed response at first time they > refuse the message. > > I'm not a truly mx expert, so what is going wrong here? I think your MX records can be regarded as broken if they point to an host without an A record. Create a DNS A record for mx0.esenf.pt, and you should be OK. It needs to point to an IP address that you own, but you don't have to have a mail server listening at that IP address. UA.PT should then check your next highest priority address, and the callout should succeed. My guess is that they aren't actually doing a callout, they're failing you for having broken MX records. > Regards, > Paulo Almeida > > -- > Escola Superior de Enfermagem do Porto > Rua Dr. António Bernardino de Almeida > 4200-072 Porto - Portugal > Tel: +351 22 5073500 - Fax: +351 22 5096337 > http://portal.esenf.pt > > > > -- > Escola Superior de Enfermagem do Porto > Rua Dr. António Bernardino de Almeida > 4200-072 Porto - Portugal > Tel: +351 22 5073500 - Fax: +351 22 5096337 > http://portal.esenf.pt -- Ian Eiloart IT Services, University of Sussex x3148 -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
