NPrinting SMTP Connectivity Issue

[rahulfundnani]

Hello Everyone,

I am facing some connectivity issues with the SMTP server that is currently being used for sending NPrinting reports due to mails are not being sent to almost 90% of the users. These are the most recurring issues which are found in the logs:

1. Failed to send email for user. ERROR: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 
2. Failed to send email for user. ERROR: Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host. ---> An existing connection was forcibly closed by the remote host
3. Failed to send email for user.ERROR: Unable to write data to the transport connection: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ---> A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

The IT Team intimated that everything is fine from the SMTP Server side. We have also tried sending the reports with different configurations and different SMTP Server altogether but it's still the same. Please let me know if anyone have any idea about this or has come across this issue.

NOTE: I am using NPrinting May 2022 Version SR3

[Ruggero_Piccoli]

Hi,

Most common reasons of SMTP issues are listed in the page https://help.qlik.com/en-US/nprinting/May2023/Content/NPrinting/AdministeringQVNprinting/Set-up-emai.... Please note that two factors authentication is not supported.

Based on the errors you posted it seems that the Qlik NPrinting server is opening more connections than the ones accepted by the SMTP server. Qlik NPrinting opens a new SMTP connection every time an email is ready for delivery and it is not possible to limit the number of connections opened. 

Then we have to few information to understand but I suggest you to check the SMTP server logs and the Qlik NPrinting logs to find more details. 

You can also try to create a test publish task with less reports and less recipients and check if it works.

Best Regards,

Ruggero

[rahulfundnani]

Hey Ruggero,

Thanks for the reply. We are aware of the two-factor authentication, so we are using an app password of the Gmail account instead.

The IT Team also mentioned that it might be due to the number of connections but some time back, we were able to send the reports without any failures. There was also one report which had near about 400 recipients with filters assigned to most of them and there was no such issue. To send the report to all the users at once without any failures, we have been using smtp-relay.gmail.com with the SSL port 465 which does not limit the number of concurrent sessions per task. This issue suddenly came up almost 2 weeks ago.

Our Team has checked all the NPrinting log files but there were no such insights which would help us understand the issue and the SMTP server logs had no record of the failed mails as the connection was not successful during the task when the mails failed.

We also tried publishing tasks with less reports and with only one recipient, the result was not the same always, sometimes the report went out and sometimes it failed. We also tested one more task with 27 users and the pattern we observed was, the report went out to only 3 random users, and when we decreased the report quality, the report went out to 7 random users every time.

I have also created a case for the same in the Qlik Support Portal and have uploaded all the log files but there is no active response as such. Please let me know if you can help me with it.

Thanks & Regards,

Rahul Fundnani

[Ruggero_Piccoli]

Hi,

Thanks for the support ticket with logs. Please link in the ticket this conversation so my colleagues can read our conversation and avoid duplicates. 

Did you checked the maximum allowed size of each email in the SMTP server? If you set also Folders or the NewsStand as destination of the same task I suppose you will find there all reports and you can check the sizes and if all expected reports are created. The issues with the email size and the number of connections are the most common, I think, with sending reports via email. 

It could be that the Qlik NPrinting logs show only that the emails were sent to SMTP because it is what it does. Sometime in the logs also the answers from SMTP are recorded but it is better to check the SMTP logs. 

Best Regards,

Ruggero

[rahulfundnani]

Hey,

This is the link to the case in the support portal: Click here.

I am not sure about the exact size limit of email but in our case, the email size should not be an issue because we have tried tasks with different reports which only had embedded HTML as well as test emails without the report actually attached to the email body but still there were report failures.

Also, in our case the SMTP logs only have the records of the mails that were successfully sent to the users and Qlik NPrinting logs has all the records, but the errors are the same which I have already mentioned.

Please check with the case from your end and let me know if there is anything else required. It would be very helpful if you can give some insights on this.

Thanks & Regards,

Rahul Fundnani

[David_Friend]

I posted an internal comment on your support case with a link to this post