Adjusting email settings appropriately so I don't get blacklisted

Hi there!
I just had a quick question regarding configuring the email settings in the PHP config to allow emails to be sent out faster since it has taken 2 days to send out over 3,000 emails - which I understand is a lot, however, the time it takes still needs to be reduce. Before I adjusted the settings, I wanted to know what could be changed in the PHP to make this happen. I know the current Queued Batch Size is set to one - however, if I changed this to two or three would I likely be blacklisted?