What Is an IP Warmup?
IP Warmup is the process of gradually increasing the volume of emails sent from a new or dedicated IP address to establish a positive sender reputation with inbox service providers (ISPs, such as Gmail, Yahoo, and Outlook). Without a proper warmup, emails risk being marked as spam or not delivered at all.
Why Is IP Warmup Necessary?
1. Builds ISP (Inbox Service Provider) Trust & Sender Reputation
ISPs evaluate incoming emails to determine whether they are legitimate or spam. If a new IP suddenly sends a high volume of emails without a sending history, ISPs may flag it as suspicious. A structured warmup process helps establish credibility and ensures better inbox placement.
2. Improves Email Deliverability
Gradually increasing email volume allows ISPs to recognize your sending patterns. A well-executed IP warmup reduces the risk of emails being blocked or sent to spam folders, improving overall email deliverability rates.
3. Protects Your Brand’s Email Performance
A poor sending reputation can have long-term consequences, including lower engagement rates, increased bounce rates, and potential blacklisting. IP warmup prevents these issues and ensures emails reach the right audience.
Key Components of a Successful IP Warmup
1. Gradually Increasing Send Volume
IP warmup follows a structured schedule, starting with a small number of emails and gradually increasing the volume over several weeks. This controlled growth helps ISPs recognize the sending pattern as normal. Here is a sample of what a 50,000 person daily send volume IP Warmup could look like:
| Email Campaign | Send Day | Daily Volume per IP | Row Ending in |
| Email 1 | Day 1 | 200 | 201 |
| Email 1 | Day 2 | 500 | 701 |
| Email 1 | Day 3 | 1,000 | 1701 |
| Email 1 | Day 4 | 2,000 | 3701 |
| Email 1 | Day 5 | 5,000 | 8701 |
| Email 1 | Day 6 | 10,000 | 18,701 |
| Email 1 | Day 7 | 20,000 | 38,701 |
| Email 2 | Day 8 | 40,000 | 78,701 |
| Email 3 | Day 9 | 50,000 | 128,701 |
2. Sending to Engaged Recipients First
To establish a strong reputation, warmup emails should be sent to the most engaged recipients first—those who have recently opened or clicked on previous emails. This signals to ISPs that your emails are wanted and valuable.
3. Using High-Quality, Engaging Content
Emails should include clear calls to action and engaging content that encourages interaction. It is important to keep in mind that the subject of the email should remain general enough to be relevant to your entire database. For example:
✅ “Click here for an exclusive offer!”
✅ “Vote for your favorite menu item in our latest poll!”
✅ “Come Visit our newest location”
✅ “What your favorite dish says about you”
✅ “Check out this month's newsletter”
Emails should avoid becoming too specific as to avoid alienating a portion of your database, as the emails should be sent to your entire database.
4. Continuous Monitoring & Adjustments if needed
Ongoing monitoring of key email performance metrics—such as open rates, bounce rates, and spam complaints—helps ensure the warmup process is effective. If issues arise, adjustments can be made to avoid deliverability problems.
Brand Responsibilities
To ensure a smooth and successful IP warmup, the brand is responsible for the following:
1. Complete Implementation Steps
- The brand must complete all required implementation steps as outlined by their MA Implementation Specialist to ensure a seamless IP warmup process.
2. Provide a List of Marketable Individuals
- The brand must provide a CSV file containing all individuals they wish to market to, ensuring that all recipients have opted into email marketing.
- This file should be submitted to the Implementation Specialist as part of the implementation steps.
3. Build All Required IP Warmup Templates
- The brand is responsible for creating all necessary IP Warmup email templates as outlined by their Implementation Specialist. The amount of email templates that need to be built will be dependent on the amount of individuals you are wanting to communicate with on a daily basis (most brands end up building somewhere between 1-5 emails templates, but that can be more depending on the size of your database).
What Happens If IP Warmup Is Skipped?
Skipping IP warmup or sending too many emails too soon can lead to:
❌ High bounce rates due to poor repudiation and email blocks
❌ Emails landing in spam folders instead of inboxes
❌ ISP blacklisting, making future email campaigns ineffective
Maintaining a Warm IP
Once the warmup is complete, it’s important to maintain regular email sending. If email activity drops significantly, the IP may “cool down,” requiring another warmup period.
Additional Notes:
- Think of an IP Warmup like blowing up a balloon, you wouldn’t want to blow it up fast as the balloon will burst! It is best to blow up the balloon slowly until you achieve the necessary size.
- An IP Warm-Up should be designed to warm-up to your brand's expected total daily volume send, not simply their entire CRM database (though we recognize your daily send volume could be your entire database). The expected total daily volume sent will determine the schedule for the IP Warm-Up.
- For example, if a brand has 500,000 guests in their CRM but they only send a total daily volume of 100,000 emails, then the IP Warm-Up should be designed to support the total daily volume sent of 100,000 emails.
- For example, if a brand has 500,000 guests in their CRM but they only send a total daily volume of 100,000 emails, then the IP Warm-Up should be designed to support the total daily volume sent of 100,000 emails.
Bottom Line: IP warmup is essential for ensuring your emails reach your audience, maintain engagement, and protect your brand’s sender reputation. Investing time in this process leads to long-term email marketing success.