I have 4,000+ members and I wish to send a mass email. In checking for queuing (queueing?), I've seen people complain on the phpbb3 support forum that emails are not being throttled, even when they've set the batch size very low. Since my host limits emails to 1,000 per hour and fails any messages above that limit, I decided to have a looksee at the code before attempting to send the mass email.
In includes/functions_messenger.php, $num_items seems to be used to control how many messages are sent in the current execution of the function. It appears that $num_items is set properly at first, but then overridden and set to the total number of messages in the queue if the number of messages in the queue is 2.5 times the batch size.
It seems to me to be completely overriding the user's configuration defeating the purpose of the queue, and the configuration limit.
Some hosts have a very strict limit on number of addresses per batch. For instance, one host in particular has a limit of 4. This approach would not ever work for anyone on that host attempting to send more than 10 messages at a time.
I believe the following code should be removed as its current operation appears to be incorrect.