For a while now, I've had this problem whereby I get multiple, identical admin emails, instead of a single one, when a user submits a survey. Sometimes I get literally DOZENS of these admin emails, spaced just seconds apart for a single submission. They all have exactly the same seed value, identical survey start and last activity timestamps, as well as the rest of the message content. The detailed headers (see attached examples) tell a different story: they show that the LimeSurvey is issuing multiple PHPmailer commands to repeatedly send out the message. This doesn't occur on every submission, but yes, on a significant percentage of them, maybe 20% or so. When it does happen, the emails keep coming sometimes for half an hour of so after the original submission. They seem to come in bursts of a few at a time, then a pause, and then some more arrive.

I have checked with the users to see if they had noticed any kind of anomaly or error after clicking the Submit button, but they don't report anything out of the ordinary. They confirm having seen the end message, as expected, and deny having clicked the Submit button multiple times. At my end, I only see a single copy of their survey responses.

I have LimeSurvey configured to send out the emails through a Gmail account, which has worked fine for the past year and a half. The problem with these bursts of duplicate admin emails has only been present in the last two versions of LimeSurvey (I am currently on 3.17.7+190627).

Have you guys heard of anything like this before? Please have a look at the attached message body and detailed headers (I have included those from two successive, duplicate admin emails for a single submission). I'd be grateful for any ideas or suggestions...

Thanks!

Try disabling AJAX in the survey theme options to ensure that the page is only submitted once.

tpartner wrote: Try disabling AJAX in the survey theme options to ensure that the page is only submitted once.

Hi, Tony. AJAX is already disabled in the theme at the global level. Do I still need to set the survey-level option explicitly to "no" instead of "inherit"?

It's worth a try. I have no reason to suggest this other than that the AJAX feature has been error-prone in this version.

tpartner wrote: It's worth a try. I have no reason to suggest this other than that the AJAX feature has been error-prone in this version.

Hi, Tony. I did what you suggested (override the inheritance and turn off AJAX explicitly) and then let the survey run for a few more days to see if it made any difference. Unfortunately, it didn't, and I am still getting multiple admin emails with some submissions. As an example, I have attached the text and the detailed headers for 4 consecutive admin emails for a single submission. You'll notice that the seed value is the same on all four emails, but the Sent and Last Action timestamps differ by a few seconds (in fact, email #3 has an EARLIER timestamp than #1 and #2!!). I have also asked the respondent directly if she had clicked the Submit button more than once or noticed any anomalous behavior thereafter, and she replied "no" to both questions: after clicking Submit (once), she immediately got the end message.

So, I am still mystified as to what's going on...

oleggorfinkel wrote: I have also asked the respondent directly if she had clicked the Submit button more than once or noticed any anomalous behavior thereafter, and she replied "no" to both questions: after clicking Submit (once), she immediately got the end message.

What are your E-Mailsettings inside LimeSurvey?

SMTP via GoogleMail? with a destination E-Mail at Yahoo?
That's what I see in the header.

I would first try to let SMTP Gmail sent to the same E-Mail adress (Gmail).

LimeSurvey is directly trying to sent an email once the submit button is clicked.
There is no queue involved. So if the SMTP is blocked, the submission of an survey gets not to the end message.
It's not that unusual to have more than one E-Mail for a submission if the SMTP communication is not 100% stable.

How many responses do you have in 24h? Can you see a pattern, when the emails come more than once? Certain times? Many responses?

jelo wrote:

oleggorfinkel wrote: I have also asked the respondent directly if she had clicked the Submit button more than once or noticed any anomalous behavior thereafter, and she replied "no" to both questions: after clicking Submit (once), she immediately got the end message.

What are your E-Mailsettings inside LimeSurvey?

Default site admin email: mim.metamindful@gmail.com
Administrator name: Oleg Gorfinkel
Email method: SMTP
SMTP host: smtp.gmail.com:587
SMTP username: mim.metamindful@gmail.com
SMTP password: ••••••••••••
SMTP encryption: TLS
SMTP debug mode: On errors
Email batch size: 50

jelo wrote: SMTP via GoogleMail? with a destination E-Mail at Yahoo?
That's what I see in the header.

I would first try to let SMTP Gmail sent to the same E-Mail adress (Gmail).

I guess I could try that... Do you think, though, that the problem could be on the receiving end (Yahoo), rather than with Gmail's SMTP server?

jelo wrote: It's not that unusual to have more than one E-Mail for a submission if the SMTP communication is not 100% stable.

Well, that could be the real answer here, although I have been using this exact setup for admin emails (Gmail SMTP to Yahoo) for quite a while and this issue only started happening a few months ago, coinciding with a LimeSurvey upgrade...

jelo wrote: How many responses do you have in 24h? Can you see a pattern, when the emails come more than once? Certain times? Many responses?

I have really tried to decipher any pattern to when this phenomenon appears, but haven't noticed anything. Some of these repeated emails come during the day, others at night. Some happen during periods of heavy traffic on the server, others when there is hardly any activity at all. One thing that's curious is that there were a couple of cases when I received literally DOZENS of admin emails for a single, successful submission, and I noticed that they were coming in bursts of a few at a time, with some significant gaps --sometimes up to an hour-- in between the batches. So, I am really at a loss here as to how to explain this... Perhaps I could try using my internet host's email server instead of Gmail and see if that eliminates the issue. I won't be able to do that, though, until at least November, when I have the next data collection period with my students.