Thanks for this very plausible reason for not doing what I wanted :-) I did not think about such circumstances.
Cheers tobi Am 07.08.2012 22:25, schrieb Reindl Harald: > > be carfeul with such things > > that you primary MX is up from the connection of your > backup-MX means virtually nothing because this does > not mean it is also from the route the delivering MTA > takes > > i have a practical example where i would 100% say it is > impossible if someone tells me the same: > > * Class C IP-Range > * two IP-Addresses on the same server > * one customer with a website on both ip-addresses > * customer has one www-domain and another domain with ip-based SSL host > > our ISP had terrible routing problems from and to all sort of > networks over some hours caused by a dying core-router > > my customer was sitting in his office on the same machine and > was able to connect to 91.118.73.6 without any problem while > he could not connect to 91.118.73.7 from the same machine while > other customers could even not connect to 91.118.73.6 > > so we had > > * the same client > * the same network hardware on the client side > * the same ISP on the client side > * the same ISp on oour side > * the same route > * the same network hardware on our side > * even the same physical server on our side > * after ISP has solved his troubles all went to normal operations > > so nobody can explain me how this was possible > but this shows me that make the decision "my primary MX is up" > is finally danherous and says virtually nothing if he is > up for any incoming connect from somewhere else and if the > primary MX is down from the delivering MTA he is absolutely > right to try the backup-MX! > >
