On Tue, 2 Nov 2010, Sabahattin Gucukoglu wrote: > On 2 Nov 2010, at 11:25, <fcxm...@aquinet.net> <fcxm...@aquinet.net> wrote: > > I found an problem in xmail when re-trying to connect to mx with multiple > > ips > > > > Here is a sample : > > Assuming domain XX.com have this dns setup > > > > xx.com mx 10 mx10.xx.com > > xx.com mx 20 mx20.xx.com > > > > mx10.xx.com A 10.10.10.1 > > mx10.xx.com A 10.10.10.2 > > mx10.xx.com A 10.10.10.3 > > > > mx20.xx.com A 22.214.171.124 > > mx20.xx.com A 126.96.36.199 > > > > supposing xmail have now to send a mail @xx.com > > on first try it use mx10.xx.com at 10.10.10.1 : now the tcp connection don't > > work > > then os same first try xmail use mx20 at 188.8.131.52 : suppose tcp connection > > don't work too ! > > > > What i see in a trace is that for ALL the others retries for this mail, > > xmail retries ONLY on SAME ips, 10.10.10.1 and 184.108.40.206 > > It never retry on others mx's ips !! And because there was no response from > > these two ips, mail bounced back to sender after all possible retries :-/ > > (i checked the others ips, they responded correctly :-/ but xmail never > > tried them ...) > > > > I think this is a major bug :( > > It's not violating the standard, but in the interests of robustness, I > agree that it is a problem. See: > http://tools.ietf.org/html/rfc5321#section-5 > > Another peculiar XMail behaviour is that even if the hostname in an MX > record is unknown, XMail logs an error but then tries again. This only > makes sense if the recipient fixes his MX records, which I think is more > likely if the mail is permanently failed rather than temporarily. In > Postfix, it's user-configurable which method is used. Again, no > violation of the spec, but my preference is for a behaviour that is > somewhat more robust, especially today with spam-filled queues > everywhere.
Note that if the remote domain would properly implement RR DNS, the issue would not arise, as the IP list would be permuted at every lookup. Of course, people does RR DNS with TTL of one day, which kinda defeats the purpose. XMail could do its own random-pickup in the supplied list, but this is really not its own task. - Davide _______________________________________________ xmail mailing list email@example.com http://xmailserver.org/mailman/listinfo/xmail