e-mail queue issues: email sent multiple times, stuck in 'sending'

e malueg asked on December 29, 2014 17:29

We are having issues with the Kentico 7 e-mail queue. Our site does use the queue, and the scheduled task is running.

New emails ARE actually being sent from our BizForms, but the status never changes from 'sending'. I will received the mail in my inbox, but if I go look at the queue it still says 'sending' with no error message or 'last send attempt' timestamp.

It also seems to continue to re-send that email multiple times until it is manually deleted from the queue. I've received a duplicate email sporatically (10 times in 3 days), but the status still says 'sending'.

Does anyone know how to correct this?

  • e

Recent Answers

Sandro Jankovic answered on December 30, 2014 10:21


Would it be possible to confirm which hotfix the instance is running? There were a few bugs in v7 that were resolved in later hotfixes.

If you try another SMTP such as Gmail does the issue persist?

Also, are you using the autoresponder/notification e-mails for BizForms or sending through custom code? Do you have this issue with all e-mails?

Best Regards,


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e malueg answered on December 30, 2014 15:18

We are running 7.0.94. I know that is a little out of date but the list of problems related to the email queue seem to be for versions prior to ours.

We are using the Kentico e-mail queue directly, and have the issue with any e-mails sent through the Kentico e-mail queue. I can actually get the error to occur without using BizForms at all, just by use the 'send e-mail' option of the e-mail queue directly.

I haven't been able to get gmail smtp to work though i followed the advice listed here: http://devnet.kentico.com/articles/how-to-configure-gmail-as-the-smtp-server. I get "No connection could be made because the target machine actively refused it"

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Brenden Kehren answered on December 31, 2014 01:52

What's your environment like?

  • Do you have your site on a web farm?
  • Does your SMTP relay require authentication or SSL?
  • Do you have any custom code putting emails in the queue?
  • Does this happen on every email that goes out?
  • Have you turned on email logging to the file system in your web.config?
  • Have you checked your event log for any errors?
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e malueg answered on January 5, 2015 15:44

  • Single Server
  • No authentication or SSL required
  • No custom code around the queue. I can recreate with the out of the box 'Send e-mail' option from the e-mail queue section.
  • It does appear to happen with every email that gets into the queue. However, Kentico has no issues sending emails in other ways, such as when i reset a password for a user.
  • Yes, i have turned on the logging. I see the recipient and subject of the expected emails dumped to the file.
  • the event log has no errors around the time of testing.

We have our scheduled task set to send emails every 15 minutes. I notice that after i send a 'test', it will stay in 'sending' mode and resend multiple times, though not EVERY 15 minutes. example: it sent this morning at 2:17, 2:33, 2:48, 3:03, 3:18, 3:33, then not til 4:50. It will go hours without sending. As i'm typing this i created a new test. I submitted it 20 minutes ago and forced the scheduled task to kick off. No email yet but it is listed as 'sending'.

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Sandro Jankovic answered on January 6, 2015 10:54


While we investigate the possible causes, could you please enable papercut as your SMTP to eliminate the possibility of issues with the email server?

As for the scheduled task differences in send times, this could be caused by the application idle timeout. If your site does not get any visits for the specified period of time, the application could time out which means the scheduled task cannot run.

Best Regards,


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e malueg answered on January 22, 2015 17:26

Sorry for the delay in response. I was able to recreate a similar situation in our development environment using papercut. With papercut running, I did a manual 'Send e-mail' from the email queue screen. When i kicked off the email queue scheduled task, I received the email in papercut, but the message was still listed as 'Sending' in the email queue itself.

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Filip Ligač answered on February 1, 2015 10:41 (last edited on February 1, 2015 10:41)


Could you please check if by any chance you still do not have the default localhost SMTP server configured in Settings -> System -> E-mail -> Default SMTP server?

If so, you need to specify your existing one or choose one from the list in SMTP servers application.

Best regards,


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e malueg answered on February 2, 2015 16:24

We do have the Default SMTP server set to our company's SMTP server. We specify the domain of our server explicitly, we don't have a list of servers to choose from. The Administration->SMTP Servers page is actually unavailable from our site, with a message "The requested feature is not available in the CMS edition you are using. See event log for more details".

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Martin Danko answered on February 23, 2015 02:23


Yes, because multiple SMTP servers could be used with the EMS edition of Kentico only. What kind of SMTP service are you using?

Also, when you are testing this, could you please confirm that there are no emails in the email queue before?

And definitely.. I would recommend you to apply the latest hotfix for Kentico 7, there were some related bugs fixed. Do you also consider upgrading to the latest version of Kentico? Email provider was improved, so it could also help.

Regards, Martin Danko

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