Email deliverability can be influenced by many factors – domain reputation, email content, or even by the type of your email.

An IP address is one of those factors and if you have a new one, it can negatively influence the success of your email campaigns.

The Solution? A process called IP warmup.

This article will help you better understand what an IP warmup is and why you need it as well as show you the best IP warmup practices that you should keep in mind when warming up your IPs.

What is IP warm up?

IP warmup (or IP warming) is a process of sending emails from a new (or cold) IP address and gradually increasing send volumes according to a predetermined schedule in order to establish a positive reputation for the given IP address.

An IP address is a unique set of numbers that identifies your email domain. ISPs (Internet Service Providers) use your IP address to track and evaluate your email activity and, in the end, to determine your IP reputation.

If an IP address is entirely new, you need to warm it up first in order to achieve high email deliverability of your email campaigns.

Why is IP warm up important?

The purpose of IP warmup is to improve your IP reputation and gain ISPs’ trust so all your emails can be delivered right into recipients’ inboxes (and not be blocked by spam filters).

Whenever you start sending emails from a completely new IP address with zero reputation, ISPs and ESPs (Email Service Providers) can get suspicious about it and prevent your IP from delivering a larger number of emails at once until you “prove” that you are a reliable sender.

Once ISPs have some historical data about your IP address and your email activity, they will allow you to send more emails to a larger number of people – or vice versa, throttle your email volumes if you start to have a bad IP reputation.

IP warmup helps to create a positive reputation for your new IP by gradually sending a larger and larger number of emails over a period of several weeks until it’s ready and properly “warmed up” for real email campaigns.

What impacts IP reputation?

An IP’s reputation can be influenced by many factors such as:

Spam reports – the number of spam complaints that your IP receives.

Delete rate – the number of recipients that moved your emails into their trash folder.

Bounce rate – the number of emails that were not delivered to recipients’ inboxes.

Engagement rate – the number of people who opened, replied to, or forwarded your emails.

Unsubscribe requests – people who unsubscribed from your email list.

Email content – the quality of your messages, grammar mistakes, usage of spam words, the trustworthiness of included links, etc.

Blacklists – The reputation of an IP address can suffer if it is put on one of the popular email blacklists.

And many other factors…

It’s important, though, to understand that not all of these components carry the same weight.

For example, the IP reputation won’t be dramatically influenced if some people unsubscribe from your email list – on the other hand, having many spam reports can severely damage the reputation of your IP.