I'll prefer to send as much as is within the limits of sending.
Can't give a specific figure as the list of users is growing and the number would increase over time.
I prefer all the emails to be send within 15mins if possible. They are all meant to get their emails between 8:00am and 8:15am.
Because of the nature of the website (its a daily news update site), the newsletter have to be created the same morning say between 6am and 8am