Re: mx selection order
On Tue, Feb 22, 2011 at 04:37:03PM -0500, David Sparro dspa...@gmail.com wrote a message of 24 lines which said: it is up to the application how it will use the data. MX records are only used by MTA and, no, it is NOT up to the MTA to decide how to handle MX records, there is a standard for that, RFC 5321, section 5.1. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: mx selection order
On 2/23/2011 4:56 AM, Stephane Bortzmeyer wrote: On Tue, Feb 22, 2011 at 04:37:03PM -0500, David Sparrodspa...@gmail.com wrote a message of 24 lines which said: it is up to the application how it will use the data. MX records are only used by MTA and, no, it is NOT up to the MTA to decide how to handle MX records, there is a standard for that, RFC 5321, section 5.1. Yes, but according to the RFC there is room for the MTA to make some administrative decisions on which MX records to use: However, there MAY also be a configurable limit on the number of alternate addresses that can be tried and If there are multiple destinations with the same preference and there is no clear reason to favor one ... I'll bet that different MTAs have different definitions of 'clear reason.' and Although the capability to try multiple alternative addresses is required, specific installations may want to limit or disable the use of alternative addresses. -- Dave ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: mx selection order
Dnia 2011-02-22 20:29 Terry. napisał(a): Hello, Given I have these MX records: example.com.3600IN MX 10 m1.example.com. example.com.3600IN MX 10 m2.example.com. example.com.3600IN MX 20 m3.example.com. My question is, when m1.example.com is failed to communicate with, the remote MTA will continue to talk to m2 or m3? From the beginning: MTA should randomly try m1 or m2, if it fails then the other one, and if both fail than m3. algorithm is simple: try random one from amongst ones with lowest precedence, discarding those failed. Torinthiel ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: mx selection order
On 22.02.11 20:29, Terry. wrote: Given I have these MX records: example.com.3600IN MX 10 m1.example.com. example.com.3600IN MX 10 m2.example.com. example.com.3600IN MX 20 m3.example.com. My question is, when m1.example.com is failed to communicate with, the remote MTA will continue to talk to m2 or m3? It seems that RFC5321 orders to try SMTP servers with lowest priority first, but allows limiting or disabling this feature for specific installations. -- Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. Chernobyl was an Windows 95 beta test site. ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: mx selection order
On 2/22/2011 7:29 AM, Terry. wrote: Hello, Given I have these MX records: example.com.3600IN MX 10 m1.example.com. example.com.3600IN MX 10 m2.example.com. example.com.3600IN MX 20 m3.example.com. My question is, when m1.example.com is failed to communicate with, the remote MTA will continue to talk to m2 or m3? That is a question you would have to ask of the remote MTA. DNS will just serve the data, it is up to the application how it will use the data. -- Dave ___ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users