Currently I have over 1500 customers and everytime I go to send a newsletter or product notification, it would just show that it is processing for a LONG time. Now I am not sure how long I should wait or maybe it timed out.... So everytime, after maybe 1 hour, I would just close the broswer not knowing if it all got sent.....

What should I do in this case?? Wait it out or is there a way I can tell it is being sent...