Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-29 Thread John Levine
In article you write: >Suresh Ramasubramanian wrote: > >> A domain with a null mx may well originate email >If they try to do that they will be sad. RFC 7505 section 4.2 agrees with you. Section 4.1 suggests

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-29 Thread Tony Finch
Franck Martin via mailop wrote: > > This could be true but then RFC7505 is recent, so I'm not sure that proper > MTAs are yet properly behaving. I wonder what sendmail, postfix, exim > really do? Exim has treated null MXs as invalid since 2004.

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-29 Thread Tony Finch
Suresh Ramasubramanian wrote: > A domain with a null mx may well originate email If they try to do that they will be sad. A lot of MTAs will reject email with a MAIL FROM using a domain that is invalid according to the DNS, and a null MX counts as invalid for this purpose.

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-28 Thread Mark Jeftovic
My test with postfix yielded: Status: 5.4.4 Diagnostic-Code: X-Postfix; Name service error for name=abx.ca type=MX: Malformed or unexpected name server reply so at least it hard failed. - mark On 2016-02-28 12:07 AM, John Levine wrote: >> What is an MTA supposed to do with a message

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread John Levine
>What is an MTA supposed to do with a message addressed to a domain with >a NULL MX? Reject it with a 556 status code and 5.1.10 enhanced status code. If the message was already relayed, return a DSN if it makes sense. See section 4.1. You can also feel free to reject mail if the return

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread Michael Wise
; Sent: ‎2/‎27/‎2016 8:12 PM To: Michael Wise<mailto:michael.w...@microsoft.com> Cc: Franck Martin<mailto:fmar...@linkedin.com>; Mark Jeftovic<mailto:mar...@easydns.com>; mailop<mailto:mailop@mailop.org> Subject: Re: [mailop] proper NULL MX behaviour for MTAs? If there's a

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread Michael Wise
l.com>; mailop<mailto:mailop@mailop.org> Subject: Re: [mailop] proper NULL MX behaviour for MTAs? On Sat, Feb 27, 2016 at 7:23 PM, Mark Jeftovic <mar...@easydns.com<mailto:mar...@easydns.com>> wrote: On 2016-02-27 9:59 PM, Suresh Ramasubramanian wrote: > A domain

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread Franck Martin via mailop
If a domain is telling me it does not accept emails, why should I accept mail from such domain if I cannot reply back to it? On Sat, Feb 27, 2016 at 6:59 PM, Suresh Ramasubramanian wrote: > A domain with a null mx may well originate email but will absolutely not > receive

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread Mark Jeftovic
On 2016-02-27 9:59 PM, Suresh Ramasubramanian wrote: > A domain with a null mx may well originate email but will absolutely not > receive email - so mail gets trashed at your end as well without staying > endlessly on your mall queues > > You can possibly correlate that mx with the behavior

Re: [mailop] proper NULL MX behaviour for MTAs?

2016-02-27 Thread Suresh Ramasubramanian
A domain with a null mx may well originate email but will absolutely not receive email - so mail gets trashed at your end as well without staying endlessly on your mall queues You can possibly correlate that mx with the behavior of domains that are sending you mail.. Though a domain rather