How Warm is Warm? Thinking About Your IP Address Warm-Up Process

minute read

Post Image

You’ve kicked around the idea for years, and finally made the decision to switch to a different email service provider. Or maybe your subscriber list has reached a point in volume where you feel it’s necessary to spread out to another IP address. Maybe you just want a dedicated IP for those transactional emails you’re sending. Whatever the reason, you have acquired a new IP address and are now facing one of those dreaded deliverability best practices: warming it up.

One thing to keep in mind is the reasoning behind IP address warming. Ultimately, you want to establish a good reputation so your mail lands in the inbox. From a mailbox provider’s perspective, when they see mail coming through from an unknown IP address, they are immediately going to be suspicious and assume this is spam trying to infiltrate their customer’s inbox. Much like the way you wouldn’t let 20,000 complete strangers march into your house, mailbox providers act in a similar manner when it comes to allowing mail to enter from a new IP address. 

So what to do? To ease the nerves of mailbox providers and reduce the risk of a new IP address having harmful effects on your reputation, as well as deliverability, consider the following:

  1. Consistency: This is a basic, key element that often gets overlooked during the warm-up phase. Whether it’s consistency in volume or frequency, mailbox providers will notice trends in your mailstream. They start to recognize your IP address and become familiar much quicker when a pattern is evident. Obviously a company with many different lines of businesses may have multiple lists of varying sizes, and at Return Path we work to customize this process based on client data. That said, while the ideal scenario is to designate sends broken out by mailbox provider on a daily basis, there are additional tactics to employ, consistency being one of the simple ones.  
  2. Target your most active and engaged users: Even with a fully warmed IP address, mailbox providers such as Yahoo and Gmail base their filtering decisions heavily on user engagement. This is why especially during the initial phase of warming up a new IP address, you really want to weed out any inactive subscribers and include active users only. While you may be hesitant to use this audience as the front lines of the warm-up, since this is likely your moneymaker group, in the end it’s the quickest way to build your reputation and expedite the warm-up process.       
  3. Sign up for feedback loops and ensure complaint suppressions are in place: Feedback loops are a valuable tool, and even more so when beginning to send volume on a new IP address. Anytime someone marks one of your emails as spam, this gets documented as a complaint. Along with inactive users being targeted, complaints are the sure shot way to damage your reputation and ultimately get your messages sent to the spam folder. Feedback loops will give you the insight that’s needed to see who has marked your email as spam. With that knowledge, you should implement complaint suppressions and ensure those individuals do not receive future mailings so your reputation can continue to grow and move in the right direction.
  4. Check bounce logs: Checking your bounce logs is an additional step you can take to confirm that you’re targeting the right people, and also removing the bad ones. If an unknown user or invalid email address exists on your list and bounces back, this should be treated similar to a complaint and suppressed right away. The last thing you want is to have an email address that is actually allowed through the mailbox provider's gateway, but then bounced back because the address no longer exists. If step 2 listed above is properly implemented, this will eliminate such bounce issues, but monitoring these logs and acting accordingly still acts as a secondary line of defense.
  5. Anticipate problems that may occur: So you’ve begun your warm up process, your first day of sending volume has fully deployed, and you already notice your IP address has a low Sender Score. Don’t hit the panic button just yet. Patience is a virtue in this scenario. If an aggressive approach is needed, maybe consider scaling down on your send volume. It’s really a matter of sending your mail, monitoring the results of those sends, and seeing what needs to be adjusted, if anything at all. 

IP address warm-ups can be stressful, but with patience, awareness, and smarter sending, it can be a very seamless process. While there is no single formula or standard “right” way of warming up a new IP address, keeping these steps in mind will put you on the path to a smooth transition from a cold IP address, to a warm one ready to handle your usual distribution.



BriteVerify email verification ensures that an email address actually exists in real-time


The #1 global data quality tool used by thousands of Salesforce admins


Insights and deliverability guidance from the only all-in-one email marketing solution

GridBuddy Cloud

Transform how you interact with your data through the versatility of grids.

Return Path

World-class deliverability applications to optimize email marketing programs

Trust Assessments

A revolutionary new solution for assessing Salesforce data quality


Validity for Email

Increase inbox placement and maximize subscriber reach with clean and actionable data

Validity for Data Management

Simplify data management with solutions that improve data quality and increase CRM adoption

Validity for Sales Productivity

Give your sales team back hours per day with tools designed to increase productivity and mitigate pipeline risks in real-time

DemandTools Elements Features

DemandTools Features

GridBuddy Connect Features

Everest Features

Everest Features