Used to be that TCP was only used for zone transfers. Normal DNS queries use UDP.
http://www.linuxnix.com/tricky-question-what-protocol-tcp-or-udp-dns-server-uses-when-a-client-queries/ On Wed, Jun 21, 2017 at 7:45 AM, Tonix - Antonio Nati <to...@interazioni.it> wrote: > It looks like nameservers of grupodecor.com do not answer to TCP queries. > > http://dnscheck.pingdom.com/?domain=grupodecor.com&; > timestamp=1498055971&view=1 > > Regards, > > Tonino > > > Il 21/06/2017 14:01, Jeff Koch ha scritto: > > Hi Boheme: > > Sorry If I was rude - I do appreciate your response on 6/12 and I > considered the two solutions you recommended. > > With respect to routing the mail through mailcleaner - if I understand the > purpose of this recommendation - I don't think the problem has anything to > the contents of the email we are trying to send. Qmail is saying that it > couldn't find any host named grupodecor.com. So it's an issue on the side > of our sending mailserver and I'd really like to understand how our > mailserver came to that conclusion - what exactly is qmail testing to > determine that. > > With respect to your second recommendation about installing djbdns we > already have a BIND server running on our network and I prefer not to > install another DNS server ( I will if I absolutely have to.) > > The problem here does not seem to be related to Outlook 365 since we are > able to send email to many other domains with email hosted by Outlook. > > I really would like to understand what's going on in the qmail code that > is causing qmail to come to the conclusion that it can't find this host. ( > What exactly does qmail mean by 'host' ? Does this mean qmail can't find > the DNS zone? Can't find an 'A' record or host? Can't find the MX record or > host?) > > Jeff > > > > On 6/20/2017 11:34 PM, Boheme wrote: > > I replied with two solutions to this problem on 6/12. > > You never replied, so I have no idea whether you tried my suggestions. > > -Sent from my Pip-Boy 3000 > > On Jun 20, 2017, at 8:10 PM, Jeff Koch <jeffk...@intersessions.com> wrote: > > > I'm having trouble sending email to anyone at grupodecor.com. All of my > qmail mailservers say: > > Sorry, I couldn't find any host named grupodecor.com. (#5.1.2) > > And yet I can send from my hotmail account and the MX host - > grupodecor-com.mail.protection.outlook.com - responds to smtp > connections. Try sending an email to anyone at that domain ( like abcde@ > grupodecor.com ) > > Anyone know why thisis happening? > > Jeff > > > > > -- > ------------------------------------------------------------ > Inter@zioni Interazioni di Antonio Nati > http://www.interazioni.it to...@interazioni.it > ------------------------------------------------------------ > >
