Limit emails per minute

[vlilloh]

Hi,

Is there any way to limit the number of emails per minute, per hour, ... in automatically Notify Users?

My server administrator tells me that the limit is around 80 emails per minute. And OJS seems that sends more than that amount and the server blocks all emails.

Cheers.

[asmecher]

Hi Vicente,

Hmm, I'd suggest checking your logs to see if there's evidence of someone using OJS to relay email. There are settings in config.inc.php, e.g. time_between_emails and max_recipients, that apply to non-editorial users. Or do you think this is arising because of the "Notify Users" mailouts?

Regards,
Alec Smecher
Public Knowledge Project Team

[vlilloh]

Hi Alec,

Sorry, I myself attempt Notify Users, after publishing a new issue, but there is a firewall on the server blocking sending mass emails. The server administrator told me that I can skip this firewall if I send about 80 emails per minute or less. If I send more than 80 emails per minute, the firewall is enabled and blocks the sending of all emails. The firewall rules can not be changed.

time_between_emails and max_recipients parameters is the solution? What might be the appropriate values ​​for example in my case?

Cheers.

[asmecher]

Hi Vicente,

I see. There's no email throttling code currently in OJS, but I expect you'll only ever encounter this with the Notify Users feature, so I'd suggest considering two options:

• Export your mailing list to an external tool for the mass mail-outs, or
• Modify the mass-mailing code, lib/pkp/classes/mail/MassMail.inc.php, to introduce a delay between MailTemplate::send() calls.

PHP isn't great at performing batch jobs, i.e. as they get longer and longer there is more likelihood that the job will be killed by the web server, but unfortunately there's not much we can do about that.

Regards,
Alec Smecher
Public Knowledge Project Team

[vlilloh]

Hi Alec,

I like the MassMail.inc.php option. Is it difficult to insert a delay? Is it enough to change any parameter as "frequency" or "set_time_limit" in this file? Or programming/PHP skills are needed?

Cheers.

[asmecher]

Hi Vicente,

Just throwing code off the top of my head -- look in MassMail.inc.php for the loop:

Code: Select all

foreach ($realRecipients as $recipient) {

Just above that, initialize the $lastSendTime variable:

Code: Select all

$lastSendTime = 0;

Then, just inside the top of the loop, add a check and possible delay:

Code: Select all

    if ($lastSendTime == time()) {
        sleep(1);
    }

...and, inside the bottom of the loop...

Code: Select all

$lastSendTime = time();

This is untested but should work. Note that it'll send out mass email sending *tremendously* -- to around one email per second -- so consider your number of subscribers and multiply accordingly. Watch out for PHP time limits or impatient browsers, which may cause PHP-based batch jobs like this to fail partway through. If that happens, you'll probably have to look into other ways of sending mail, as PHP is not good at long jobs.

Regards,
Alec Smecher
Public Knowledge Project Team

[vlilloh]

Hi Alec,

Thank you very much! Ok, I'll test this to see how it goes.

Cheers.