IP Warming is the process by which you gradually increase the total amount of emails sent from an IP address to increase/improve the sending reputation of the said IP address. This process is aimed specifically at building/establishing a reputation with Internet Service Providers (ICPs), where the overall health of a domain and associated email addresses is based upon the ISP reputation of the server.
Why Is IP Warming Important?
To put it in simple terms, IP Warming is important because it directly affects how effective your email deliverability rates are. You need to demonstrate through consistent positive engagement that your domain is trustworthy and not sending out spam mail.
How Does IP Warming Affect Email Deliverability?
Newly registered domains and newly created IPs are inherently more prone to having outgoing mail be blocked, deferred, or even blacklisted simply due to their being little to no past sender history. Warming up your IP Address is important simply because it gives you a positive, baseline reputation out the gate so that there are no issues when you begin sending mail.
How Is IP Warming Related to Inbox Warming?
Inbox Warming and IP warming are essentially the same. The primary difference between the two is that IP Warming can be done across multiple email addresses while Inbox Warming is related specifically to an individual inbox. Both activities will boost the reputation of your domain and inbox.