Failed to send e-mail message with error message "No such host is known"

[rohitk1609]

Hi Techies,

Suddenly we are receiving error messages in Task Execution log:

I have checked the logs and below message is there for multiple users 

ERROR  QLKNPRNT  0 0 0 0 0 0 0 0 Failed to send e-mail message to xxxxxxxx@xxxxx.com. ERROR: System.Net.Sockets.SocketException (0x80004005): No such host is known↓↓ at System.Net.Dns.GetAddrInfo(String name)↓↓

It has started from last week and occurs randomly.

Can anyone help us to fix it ?

Thanks,
Rohit

[Frank_S]

Hi @rohitk1609 

The message may be due to a dns issues in your environment. The problem is being logged by NP logging services.

• Check the NPrinting Email SMTP Settings to ensure that valid information is entered. You must be an NP admin to do this.
• Whitelist your NP server on the email server/clustered email server configuration to allow all mail from the NPrinting server computer.
• Note that NP server is not an email server. It is simply an email client that sends email to an email server configured in the NP web console email settings.

See the following for additional information.

• https://support.qlik.com/articles/000028776

[rohitk1609]

Hi Frank,

Please find my inputs on your points:

1. Yes I am admin and smtp settings are correctly configured. I sent few test emails and emails are being sent to recipients but failing for few.

2. It is started from last few days.

3. If I need to whitelist my NP server on email server, how it was sending email and still sending for most of the recipients  ? I can check with my SMTP team.

4. Can you please help me to ask right question to SMTP team , what exactly they need to check at their side ?

Thanks,
Rohit

[Frank_S]

Thank you for your answers @rohitk1609 

• Emails are sent in series by NPrinting so each email goes out one at a time. They are not bursted all at the same time by the NP server. You can see this by viewing the time stamps of each delivery attempt. So while one goes out, the dns connectivity/failure may exist in the next attempt and work again later if the dns is working again.
• In any case, you can simply show your email admins the logged failure information from the NP server, give them the NP server name and IP address as well so it can be white-listed accordingly.

Kind regards...

[rohitk1609]

Hi Frank,

My SMTP IT team is saying they haven't changed anything since years. 

IT team is checking the DNS of Qlik Server which is connected with NP Printing server. May be DNS of Qlik Sense server is failing.

Thanks,

Rohit

[Frank_S · Accepted solution]

Yes @rohitk1609 

It is likely then that DNS on your servers are the problem if there is no issue with the email host itself. The DNS may have intermittent issues which is affecting your NPrinting distribution with the NP logs are capturing.

[rohitk1609]

Hi Frank,

My only question here is:

when this error comes

ERROR  QLKNPRNT  0 0 0 0 0 0 0 0 Failed to send e-mail message to xxxxxxxx@xxxxx.com. ERROR: System.Net.Sockets.SocketException (0x80004005): No such host is known↓↓ at System.Net.Dns.GetAddrInfo(String name)↓↓

what extactly HOST refers to, Host of email of recipient or host name of NPrinting server or host name of Qlik Sense user with which connection of NP has been established ?

Thanks

Rohit

[Frank_S]

@rohitk1609 "Hostname" by most standards applies to the 'computer' hostname. It has no bearing on email addresses.

In this case it is likely referencing the email server computer 'hostname' which NPrinting is attempting to connect to: ERROR: System.Net.Sockets.SocketException (0x80004005): No such host is known↓↓ at System.Net.Dns.GetAddrInfo

• https://en.wikipedia.org/wiki/Hostname
• https://support.microsoft.com/en-ca/help/2823477/test-agent-configuration-fails-with-error-system-ne...
• https://www.google.com/search?q=ERROR%3A+System.Net.Sockets.SocketException+(0x80004005)&rlz=1C1CHBF...

The above information contains information as to what a hostname is as a generally accepted term as well as a couple of search results and a google search pattern you may reference for more information about the error being logged for you via the NPrinting server.

In any case your next step is to check with your network team to determine if there is an issue with either DNS or your local hosts file on your NPrinting server computer. DNS issues can impact communications with all servers in your environment if there is a problem there or with local host files installed in the system32/etc/hosts folder.

Kind regards...

[rohitk1609 · Accepted solution]

Hi Frank,

We have updated DNS server address to new group of DNS servers and it seems issue is fixed. I will update this ticket in case issue reoccur.

Thanks,

Rohit