Unable to find the recipient's email server. The DNS query has failed.

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VadaDosaIdly
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Unable to find the recipient's email server. The DNS query has failed.

Post by VadaDosaIdly » 2021-06-12 17:29

Hello,

Recently, I noticed that one of the sent email is bounced back with SMTP error - "Unable to find the recipient's email server. The DNS query has failed. Tried 5 time(s)".

I checked the DNS query (https://intodns.com/) on their domain and validated email with email validator (https://verifalia.com/) and found no issue. Recipient is receiving emails from other people and sending emails to others. After few days, I tested sending email to another email account under same domain name and found no success (bounced back).

I am using MS Outlook 2016 as email client to send and receive emails and have no problem in sending email to others and receiving email from others.

What I am missing here? Using Version 5.6.8 - Build 2431 of hMailServer.

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katip
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by katip » 2021-06-12 18:07

in short, your DNS is not able to resolve it.
open an account at an SMTP service such as smtp2go and route your outbounds to this domain.
many have limited (reasonable) free packages.
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mikedibella
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by mikedibella » 2021-06-12 19:06

Make sure that the recipient domain's MX record Host attribute names an A record and not a CNAME for glue to the host's IP address. I seem to remember that hMailServer requires strict RFC compliance and does not resolve CNAME Host references in MX records, even though some authorities configure DNS that way.

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mattg
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by mattg » 2021-06-13 03:09

You could also try a different DNS

Which DNS are you using?
(Google's free DNS is 8.8.8.8 and 8.8.4.4)

You can use the hMailserver to check an email address, it just uses the Windows default DNS, so you'd get the same result using NSLOOKUP at a command prompy

It's also possible that you have a rogue host file entry is this is a know domain for you
Just 'cause I link to a page and say little else doesn't mean I am not being nice.
https://www.hmailserver.com/documentation

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jim.bus
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by jim.bus » 2021-06-13 10:05

Could this be a Windows ARP or Windwos DNS Resolver Cache issue?

This sounds a bit like similar problems I have viewed on the Forum before. Perhaps Windows is going to the ARP Windows Resolver Cache table to find the Domain and the entry there is not resolving to the what is on the Public DNS. You guys are more knowledgeable on this than I am but it sounds similar to what I've seen in the Forum before.

A Windows Command Prompt ipconfig /flushdns might clear the Windows DNS Resolver Cache and resolve the problem. An ipconfig /registerdns might also have to be done if this is the problem.

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SorenR
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by SorenR » 2021-06-13 11:03

Been discussed before.

viewtopic.php?p=227670#p227670

INI option "use_dns_cache=0" was added to 2.6.8 B2538.30 (RvdH) to allow bypass of Windows DNS Cache ;-)
SørenR.

Algorithm (noun.)
Word used by programmers when they do not want to explain what they did.

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jim.bus
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by jim.bus » 2021-06-13 11:36

SorenR wrote:
2021-06-13 11:03
Been discussed before.

viewtopic.php?p=227670#p227670

INI option "use_dns_cache=0" was added to 2.6.8 B2538.30 (RvdH) to allow bypass of Windows DNS Cache ;-)
But he uses B2431 not B2538.30 And could it also be ARP if not Windows DNS Resolver Cache. I know I had to on one occasion for some problem I had to edit the ARP to remove an entry which was causing me problems.

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SorenR
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Re: Unable to find the recipient's email server. The DNS query has failed.

Post by SorenR » 2021-06-13 11:59

jim.bus wrote:
2021-06-13 11:36
SorenR wrote:
2021-06-13 11:03
Been discussed before.

viewtopic.php?p=227670#p227670

INI option "use_dns_cache=0" was added to 2.6.8 B2538.30 (RvdH) to allow bypass of Windows DNS Cache ;-)
But he uses B2431 not B2538.30 And could it also be ARP if not Windows DNS Resolver Cache. I know I had to on one occasion for some problem I had to edit the ARP to remove an entry which was causing me problems.
Same effect here...

Code: Select all

Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Dnscache,
Locate the Start registry key and change its value from 2 (Automatic) to 4 (Disabled)
or here

Code: Select all

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters]
"MaxCacheTtl"=dword:00000001
"MaxNegativeCacheTtl"=dword:00000000
SørenR.

Algorithm (noun.)
Word used by programmers when they do not want to explain what they did.

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