Why does my send rate reset to 250/hour when I include new customers?
If your campaign is going to be sent to a customer base with more 5%+ new customer contacts, this will trigger one of Mailchatter's safety nets for protecting reputation. Your send rate will reset to 250/hour for that campaign until we are confident that these new customers are legitimate. If you want to take advantage of your existing high send rate for your existing customers, you should consider scheduling your email in two separate campaigns set to send at two different times. So, schedule the campaign to your existing customers first, to send at your current send rate and schedule the campaign to your new customers afterwards at the send rate of 250/hour. This send rate for new customers will, of course, increase each time you send to them and as long as the new customers are legitimate, the send rate for all your customers will shortly be aligned. We recommend that you schedule the two campaigns at least 4 hours apart.