Looking over your settings:
By the way, Dan... do you know what's the best set up for speeding up the sending by batch? I am on a VPS server but I don't want to overload my server by sending unlimited emails per hour. So I want to send using the batch processing. So what I did was to configure my phpList to be able to send 480 emails per hour. Please correct me if this is not the right configuration, as I noticed that the result did not correspond to what I've configured my phpList to do. After 24 hours, my phpList did only send 2,229 emails out of 11,520 (480/hour*24=11,520).
Here's my Queue and Load management:
("MAILQUEUE_BATCH_SIZE",120);
("MAILQUEUE_BATCH_PERIOD",900);
('MAILQUEUE_THROTTLE',5);
('MAILQUEUE_AUTOTHROTTLE',0);
('USE_DOMAIN_THROTTLE',1);
('DOMAIN_BATCH_SIZE',1);
('DOMAIN_BATCH_PERIOD',120);
('DOMAIN_AUTO_THROTTLE',1);
('MAX_PROCESSQUEUE_TIME',0);
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in 'english'.... send 120 emails every 900 seconds (15 mins), with a 5 second delay between each email,( or at the rate of 3600secs/hr / 5secs = 720/hr)
At the same time, limit the sending to any given domain at 1 email every 120 secs (2 mins), (don't send more than 30 emails/hr to any given domain i.e. hotmail)
You'll have to check with your hosting company, but it looks like they are limiting your sending to about 100/hour. 2229/24 = 93/hr. You might want to contact them to see if they can raise your hourly limit.
I've noticed that sending with DOMAIN_BATCH_SIZE = turned on will slow down your sending, so that could also be another reason that you are getting a slower sending rate. Since you are only processing the queue every 15 minutes, I'd probably put the DOMAIN_BATCH_PERIOD to 900, and recalculate the Batch Size to ~ 7 or so.
To verify what's causing the slower sending, you should test one thing at a time... ie. start by changing the DOMAIN_BATCH_PERIOD and batch size, see what happens. Then have the hosting company increase your sending limit, see if it goes out faster. Then increase your domain batch size, to say 20 or so, and see what effect that has.
One last suggestion is to increase your MAILQUEUE_THROTTLE to 9 or so... that will 'smooth out' your sending.... spread it out over the batch interval, but also fast enough so that it finishes before the next batch check time.