Hello Kyle, I just tried it again but it still does not work. There must be something missing in my system, maybe.

I setup a 4 recipients mass mail list with 2 e-mails per batch and 300 seconds pause between batches. When I hit "Send Mails" I got a message saying that two e-mails had been sent (so far so good) but maybe 5 seconds later I finally got the message that all 4 e-mails had been sent.

I am using Joomla 3.9.0 and CB 2.2.1

I would appreciate if you could give me some hint to look for the cause.

Best regards,
Fabio.

Thanks Kyle. Just noticed that CB 2.3.0 has appeared in the update list. I will update and test.

Regards,
Fabio.

Worked just fine for a pause of 300 seconds between batches. Now I need to check the points you raised when I need to pause for 1h and have two or three batches to send.

The batching works by just triggering an ajax request to send another batch meaning the window has to be left open for that to even work. This also means your login session has to continue being active. If you've 10 hours worth of emails you've to let it sit for 10 hours. That's just not practical...