For customers who send high email volume and want more control over their individual sender reputation, HubSpot offers a dedicated IP address for sending emails.
When you purchase the dedicated IP add-on, HubSpot's Email Deliverability team reaches out to your account’s primary contact to start the DNS setup process. Once the dedicated IP is live, the new IP address is warmed up gradually to establish a healthy sending reputation.
A sudden change in sending volume can look suspicious to email filters and blacklist operators. So for the first 60 days, your email tool automatically splits email sending between your dedicated IP address and some shared IPs. The tool uses an algorithm to gradually increases sending over your dedicated IP during that time.