Hello,
in the last invite sending we received lots of "550 5.7.1 [STF] Sending too fast." errors (mostly from GMail).
The whole list of invitations was about 6000 addresses.
We first set the number of invitation per batch to 50 (default), then we tried to set 10 but nothing changed.

Is there some setting i can change to slow down the pace of the emails being sent?
Or is there something else i can do to solve this?

Thanks,
Regards,

Well, Gmail is not really made for mass email sending. They have certain limits in place to keep spam being send from their servers as little as possible. You should invest in a SMTP-Email account that is made for mass emails. Please search for the Gmail limits. With a quick search I found this here:
support.google.com/mail/answer/22839?hl=en

"You have reached a limit for sending mail"
You may see this message if you send an email to a total of more than 500 recipients in a single email and or more than 500 emails sent in a day.

When you get this error, you should be able to send emails again within 1 to 24 hours.

But I think I have seen that there are even more restrictions on Gmail (e.g. hourly as well).

E.g. some information here: woodpecker.co/blog/email-sending-limits/...for%201%2D24%20hours .

According to them the daily limit of emails via SMTP is even just 100 emails (500 via the webinterface). And there also seems to be an unofficial hourly limit of around 20 emails. So Gmail is definitely not a good way when you need to send many emails at a time.

Or are you sending from another SMTP-Account and Gmail is complaining that you send too many emails to them?

In this case, you might want to read this for example:
support.google.com/mail/answer/81126?hl=...382665739-3305764358

All in all, sending mass emails is a science in itself. There are many factors to take into account to avoid to be marked as a spammer. Before sending a high number of emails, I would really look into this to make sure that you are prepared for sending this many emails.

Hello holch,
and thanks for your answer. I am sending from a "third-party" email account to gmail accounts and GMail is complaining. Our email server is definitely ready (and enough paid) so i was asking if it's possible to slow down on LimeSurvey's side since it seems there is not timeout between the batch sending in LimeSurvey.

Correct me if i'm wrong, in LimeSurvey 3 if i select all the participants and i send invitations it sends the invitations grouped by N (depending on the last setting on the "Email setting page") with no timeout until the end, doesn't it?

Am i missing something?

Thanks,

Regards,

cesoielampo wrote: I am sending from a "third-party" email account to gmail accounts and GMail is complaining. Our email server is definitely ready (and enough paid)…

It's not a LS issue here …

See with your email provider …

and thanks for your answer. I am sending from a "third-party" email account to gmail accounts and GMail is complaining. Our email server is definitely ready (and enough paid) so i was asking if it's possible to slow down on LimeSurvey's side since it seems there is not timeout between the batch sending in LimeSurvey.

That is why I asked, your innitial post was not very clear on that.

In Limesurvey you can set the batch size. Then Limesurvey only sends the number of emails you have specified in one batch. The next batch needs to be triggered manually, so it is up to you.

We first set the number of invitation per batch to 50 (default), then we tried to set 10 but nothing changed.

Is there some setting i can change to slow down the pace of the emails being sent?

The problem here is that you most probably caused Google to block you by sending to many emails to them within a certain time frame. 50 emails might already be too many for them in one batch.

The change to n=10 then didn't have an effect, because you already had sent too many emails to them. So if the n=10 was not too long after the n=50, then they registered you as someone sending n=60 emails to them, which of course for them is considered to be worse than n=50...

Did you read my second link that I posted, where Google explains what you need to do to send mass emails to them? I'll post it again:

support.google.com/mail/answer/81126?hl=...382665739-3305764358

I find especially this part interesting for your case:
"Increase sending volume slowly"

If you are sending emails to a lot of Gmail recipients, you might want to think about using their Postmaster tools mentioned in the article as well.

There is also an explanation on the 550 5.7.1 error:
"550, "5.7.1": Messages are rejected because the sending server’s IP address is on an IP suspended list. You might get this error if you’re sending mail using a shared IP with a poor reputation."

So actually your email provider might not be the "best neighborhood".

So I can only recommend to read this article, it seems to contain some very interesting information on how to make sure that your email reaches your destination, when it comes to Gmail.

Correct me if i'm wrong, in LimeSurvey 3 if i select all the participants and i send invitations it sends the invitations grouped by N (depending on the last setting on the "Email setting page") with no timeout until the end, doesn't it?

I don't usually use the email invitations, but afaik, this is wrong.

Here is what the Limesurvey manual says about email batch size ( manual.limesurvey.org/global_settings#Email_settings )

Clicking the 'send email invitation' button that is located on the token control toolbar on the right of each token sends the 'maxemails' number of invitations, displaying a list of the addresses to which the email was already delivered and a warning that "There are more emails pending than could be sent in one batch. Continue sending emails by clicking below. There are ### emails still to be sent." and provides a "continue button" to proceed with the next batch. So, the user determines when to send the next batch after each batch gets emailed. It is not necessary to wait with this screen active. The admin could log off and come back at a later time to send the next batch of invites

This was also my knowledge about sending invitations in Limesurvey. It is not an automatic process, but you need to do it manually, so you define the rythm. I am not sure if there is any plugin or script that can automate the sending of your email invitations, but the default is that you have to click to send each of the batches of invitations. So if you set the batch size to n=10, then you'll have to click 600 times to send all n=6000 invitations.

The Limesurvey template shop seems to have some cron jobs that can do this for you (never used this, not a recomendation):
survey-consulting.com/product-category/l...vey-cronjob-scripts/

And maybe Denis here has a plugin or something for this. Well, here we go, this looks like something:
gitlab.com/SondagesPro/mailing/sendMailAjax
Not sure if it will work with LS 3.x.

Or this:
gitlab.com/SondagesPro/mailing/sendMailCron

holch wrote: And maybe Denis here has a plugin or something for this. Well, here we go, this looks like something:
gitlab.com/SondagesPro/mailing/sendMailAjax
Not sure if it will work with LS 3.x.

Not beautifull, but it work
.

The only way with a broken sender (i confirm : it's not a LS issue : you pay a "third-party" email : service must be done. My server have different system for some specific email).

holch wrote: Or this:
gitlab.com/SondagesPro/mailing/sendMailCron

Worst : can send 1000 email/seconds

The only way with a broken sender (i confirm : it's not a LS issue : you pay a "third-party" email : service must be done.

I agree with you that the problem is rather with the way the SMTP service is sending the emails than with Limesurvey.

But I saw the assumption that Limesurvey would automatically send the emails in batches of X emails, in a certain intervall, until the emails are all send. Thus I tought I would add on this. Using the plugins or cron jobs will not solve the problem of the 550 5.7.1.

Hello,
so, we found out the email provider bought a service to block outbound spam and our LS installation is being seen as a spammer. So it's not a Google's problem actually.
We asked them how to solve and they told us "reduce the volume of the emails being sent".

This was also my knowledge about sending invitations in Limesurvey. It is not an automatic process, but you need to do it manually, so you define the rhythm.

But I saw the assumption that Limesurvey would automatically send the emails in batches of X emails, in a certain intervall, until the emails are all send.

We just tried to send 50 email in 5 batches of 10. When you click send it starts the sending automatically the first 10 and sends the second 10 right after. If you don't click the "Cancel the automatic sending" (maybe wrong translation from italian) it keeps sending.

So, yeah, in the end it's not a LS problem but at this point i need to find the fastest (and best) resolution.

Thanks for all the info and the links, which are really interesting.

gitlab.com/SondagesPro/mailing/sendMailAjax

Since one mail by one mail on each action, done in ajax … more than 0.2 second (if you have a really quick server) between each email.