When you send bulk emails from a new IP and domain, the behavior of the first users who open your emails has a significant impact on the ongoing inboxing process of your campaigns. If receivers mark your email as spam, delete it or not open it at all, they are sending negative signals to your ESP and it will reduce the reputation of your emails. but when users send good signals like opening your emails, mark them as not spam, and write a reply, your reputation and domain will increase and notify ESP's that your emails are valuable and should be inboxed. At Hoopoe, we provide you with a Warmup campaign panel. in order to warm up your campaign, you just need to send your campaigns to our list. after that you can start sending them to your email list.