Re: No MX, no address

[mea@nic.funet.fi]

> In article <35140C90.443667D5@ibd.es> you write:
> >Well, looking in the queue I've found this warning:
> >
> > 364811-28276:   smtp; 500 (nameserver data inconsistency. No MX, no
> >address: 'europamail.com', errno=Unknown error, gai_errno='name or
> >service is not known') (retry in 19m15s, expires in 3d14h, tries=141)
> >
> >I wonder why zmailer doesn't abort the message (europamail.com domain
> >doesn't exist) and sends an error  message to the sender. Is this a
> >correct behaviour?
> 
> Yes, this is correct behaviour:

	Yes and no.

	At the moment it is "soft" error by which I have hoped to
	give a bit of time for the destination system administrator
	to correct their DNS datasets.  If the message has not been
	delivered within scheduler channel/host selector timeout
	specification, then the "soft" error becomes "hard", and
	bounces.

	There is also a bit of timidity at my DNS routines which
	have had a lot of modifications over past two years, and
	in some versions they did yield false errors at times.
	For past (at least) 12 months I have not seen any false
	errors, so perhaps I start to believe in on it, and could
	alter it to be "hard" error -- to error right away.

	On the other hand, with this a watchfull postmaster can
	notice when target domain has trouble with it, and could
	(in theory) ask target domain admins to fix it by adding
	the missing MXes, and have emails delivered if the detection
	and correction happen early enough.

	Doing DNS code is -- a challenge indeed...

	/Matti Aarnio <mea@nic.funet.fi>

> acli@monet:~/Projects/icc/doc[792]$ host europamail.com
> acli@monet:~/Projects/icc/doc[793]$ host -a europamail.com
> Trying null domain
> rcode = 0 (Success), ancount=1
> The following answer is not authoritative:
> europamail.com  82069 IN        SOA     dns.glo.be dns.glo.be(
> [stuff deleted]
> 
> The name exists; it just has "no MX, no address" :/