Joe, A standard MTA will try a secondary MX if the available connections on the primary are exhausted. If the secondary system is not configured to relay mail for the domain then a bounce will occur as a 500 level error should be returned. I have noticed that from time to time this will happen if the primary MX is using some form of connection management, or is just under stress. You should ether configure your server to accept email for them or remove it as a secondary MX All the best. Greg Soffe Mail Administrator Telecom NZ Ltd -----Original Message----- From: Joe [mailto:h4xz0r@loose.net.nz] Sent: Friday, 22 February 2008 3:35 p.m. To: Michael Fincham Cc: nznog Subject: Re: [nznog] Xtra(Yahoo) Mail going to 2nd MX by default I would like to re-word that as reading it again It doesn't make sense to me :-/ A customer of ours runs their own mailserver, we do backup mx for them. People on xtra couldn't send mail getting a bounce back due to our secondary mailserver not accepting mail, their primary was fine however. Joe. Michael Fincham wrote:Mail server administrators do tend to deploy deliberately brokenprimaryor secondary MXs to divert spam. I cannot comment whether or notYahoo!are doing this. On Fri, 2008-02-22 at 15:29 +1300, Joe wrote:Hi All, Had a customer of ours, no one on xtra could send e-mails they justgotbounce backs. In this instance the Secondary MX was not accepting mail (The Daemonhadcrashed), the primary was fine however and no one else had issues sending mail there. Does anyone know if this is some kind of feature with Xtra's mailservers, to choose the secondary over the primary MX? Regards, Joe. _______________________________________________ NZNOG mailing list NZNOG@list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog_______________________________________________ NZNOG mailing list NZNOG@list.waikato.ac.nz http://list.waikato.ac.nz/mailman/listinfo/nznog