I have one query for slow delivery, that is , we are sent news latter to our customers , that very bulk mail,
may be that is 50 k mails per week , once stated senting mails it will start sent mail very fast , after senting 250 or 150 mails continuously AOL,hotmail, yahoo will block our IP , so we need need to sent mails very slowly , how can i do that .
Simply add the following (from config-extended) to your config.php file, adjusting the delay to suit your limits.
# to avoid overloading the server that sends your email, you can add a little delay
# between messages that will spread the load of sending
# you will need to find a good value for your own server
# value is in seconds, and you can use fractions, eg "0.5" is half a second
# (or you can play with the autothrottle below)