Thats true, I have one site that has a pretty large list thats on a seporate server and it takes about 3 hours to send out the emails. I not sure why it lags on getting them out as it finishes in about 15 minutes, but the emails just dont show up for about 3 hours.

If I am using that list on a launch I try to get the email out at exactly launch - 3 hours, if I am on the ball anyway.