Correct settings for autothrottling emails?

ℹ️ Support
1

I have about 500 subscribers. I want to send the emails out over an hour.

These are the relevant settings in my config.php:

define('MAILQUEUE_BATCH_SIZE', 500);
define('MAILQUEUE_BATCH_PERIOD', 3600);
define('MAILQUEUE_THROTTLE', 0);
define('MAILQUEUE_AUTOTHROTTLE', 1);
define('MAX_PROCESSQUEUE_TIME', 0);

But the logging email shows that only about half are being sent:

[Sun 10 Nov 2024 12:45] [CL] Sending in batches of 500 emails
[Sun 10 Nov 2024 12:45] [CL] Processing has started,
[Sun 10 Nov 2024 12:45] [CL] One campaign to process.
[Sun 10 Nov 2024 12:45] [CL] Processing campaign 18
[Sun 10 Nov 2024 12:45] [CL] Looking for subscribers
[Sun 10 Nov 2024 12:45] [CL] Found them: 469 to process
[Sun 10 Nov 2024 13:14] [CL] Processed 469 out of 469 subscribers
[Sun 10 Nov 2024 13:14] [CL] Script stage: 5
[Sun 10 Nov 2024 13:14] [CL] 246 messages sent in 1771.21 seconds (499 msgs/hr)
[Sun 10 Nov 2024 13:14] [CL] 223 failed (will retry later)

It doesn’t say why those 223 failed. 30 minutes after sending stops, it restarts but doesn’t get very far:

[Sun 10 Nov 2024 13:45] [CL] Sending in batches of 500 messages
[Sun 10 Nov 2024 13:45] [CL] This batch will be 254 emails, because in the last 3,600 seconds 246 emails were sent
[Sun 10 Nov 2024 13:45] [CL] Processing has started,
[Sun 10 Nov 2024 13:45] [CL] One campaign to process.
[Sun 10 Nov 2024 13:45] [CL] Processing campaign 18
[Sun 10 Nov 2024 13:45] [CL] Looking for subscribers
[Sun 10 Nov 2024 13:45] [CL] Found them: 223 to process
[Sun 10 Nov 2024 13:45] [CL] Processed 223 out of 223 subscribers
[Sun 10 Nov 2024 13:45] [CL] Script stage: 5
[Sun 10 Nov 2024 13:45] [CL] 7 messages sent in 50.97 seconds (494 msgs/hr)
[Sun 10 Nov 2024 13:45] [CL] 216 failed (will retry later)

If I go to process the queue manually, it seems to send one at a time.

Would I be better turning off batch size and setting a delay of, say, 6 seconds between emails?

2

Well, that didn’t work. Tried setting a 1 second delay in config.php:

define('MAILQUEUE_BATCH_SIZE', 0);
define('MAILQUEUE_BATCH_PERIOD', 3600);
define('MAILQUEUE_THROTTLE', 1);
define('MAILQUEUE_AUTOTHROTTLE', 0);

The first campaign fails halfway through:

[Tue 12 Nov 2024 12:49] [CL] 209 messages sent in 248.96 seconds (3022 msgs/hr)
[Tue 12 Nov 2024 12:49] [CL] 256 failed (will retry later)

At the next scheduled send:

[Tue 12 Nov 2024 13:45] [CL] Processed 256 out of 256 subscribers
[Tue 12 Nov 2024 13:45] [CL] Script stage: 5
[Tue 12 Nov 2024 13:45] [CL] 13 messages sent in 16.97 seconds (2758 msgs/hr)
[Tue 12 Nov 2024 13:45] [CL] 243 failed (will retry later)

Is there any way to find why sending failed?

3

The Event Log page will show any errors while sending.

4

It doesn’t seem to show anything more than the admin email:

7968 2024-11-12 12:49:11 Finished this run
7967 2024-11-12 12:49:11 256 failed (will retry later)
7966 2024-11-12 12:49:11 209 messages sent in 248.96 seconds (3022 msgs/hr)
7965 2024-11-12 12:49:11 Processed 465 out of 465 subscribers

When I manually process the queue later, I see

7976 2024-11-12 13:45:20 243 failed (will retry later)
7975 2024-11-12 13:45:20 13 messages sent in 16.97 seconds (2758 msgs/hr)

And I end up with a hundred admin emails.

Is there a way to make it instantly retry when it fails? All the emails eventually get sent - but it is pain to have to do it manually each time.

5

@edent Have you enabled domain throttling or something similar? That may be the cause of so many failures to send.

6

The default my installation had was:

define('USE_DOMAIN_THROTTLE', 1);
define('DOMAIN_BATCH_SIZE', 1);
define('DOMAIN_BATCH_PERIOD', 120);

I’ve switched that off, and will see if that works.