day limit

I understand your point, it’s an interesting alternative. But the flaw of this, and of plugin actual engine of course, is the risk of few visits to the blog, that means not-periodic batches and the daily limit cannot be reached anyway.
As suggested in plugin setting page, a good solution is to apply a real external cron job that can send a batch every precise interval and can send all the emails untill the daily limit is reached.

I did set an external cron, this quasi cron of WP is very unreliable.

Still, assume that my mailserver can handle 10k a day, 100 in a batch. In the current code you take the minimum of the 10k/batch vs. max. batch. Assume that 5 min. cron is OK.

// so... how much recipients for this interval? // (86400 = seconds in a day)
	$day_rate = alo_em_get_dayrate();
	$tot_recs = max ( floor( ( $day_rate * $diff_time / 86400 ) ) , 1 );
	// not over the limit
	$limit_recs = min ( $tot_recs, alo_em_get_batchrate () );

$tot_recs = max ( floor ( 10000 * 300/86400), 1) = 34
$limit_recs = min(34, 200) = 34.

Thus the daily limit does not allow me to reach the batch limit.

Also, have 2 other ideas:
– it would be good to automatically remove the addresses where the mail is not delivered and
– to add number of unsubscribed users to the stats page – for the given newsletter

About your ideas:
1 – You can remove the addresses where email is not delivered using plugin “bounce” function: for security reason the bounce check is not automatic anymore, you can check them manually in dashboard.
2 – Good idea, I’ll keep it in mind for future.