How to Use IP Warming to Maximize Your Email Open Rate

minute/s reading time

IP warming is essential for preparing to improve open email rates. Before exercising, you should warm up; the same goes for sending a large volume of emails! It would help if you made your IP trustworthy to ISPs (Internet Service Providers) to maximize your email deliveries so more recipients can open them.

A business should gradually increase the number of emails they send daily to warm up their IP address, as more sent-out emails increase email open rates. Additionally, they need to validate the quality of their email list to ensure maximum engagement.

Basically, a good warm up would look something like this:

IP warming helps you gain credibility, increase email volume, and manage your email campaign well, and the more emails you send, the more people open them. Email warming can also be a bit tricky but completely doable.

To help your email open rate progress through IP warming, we'll look at some things that can help you succeed in this endeavor.

Let’s get started.

1. Correctly Warm Up Your IP Address

If you send too many emails too soon, it damages your IP reputation by ISPs blocking emails or sending them to spam folders, which will take a long time to rectify. To prevent delivery problems and mail marked as spam, you'll need to correctly warm up your IP address to get a high email open rate.

By warming your IP address correctly, you build up standing with ISPs as a trusted sender, allowing you to size up the daily volume of emails you send. IP warming also entails creating quality emails and filtering your mailing list to people who will act on them, increasing your open rate.

2. Plan IP Warming to Increase Email Open Rates

IP warming is a gradual process of a daily increase in the number of emails sent over some time, typically between four to eight weeks, but it will depend on your goals and the volume of your mailing list. You'll need to plan a schedule of dates and the capacity increases.

You need to start with a small volume and build your way up to the desired number of emails you'd like to send. There are best practices you need to abide by to warm up successfully and maintain a good reputation with ISPs.

Pro tip: Your first email recipients should be those who engage with your emails the most so you can gain trustworthiness before moving on to a less interactive audience.

3. Monitor Mailing Lists for Email Open Rates and Engagement

Open rates and engagement are prime factors in IP warming, contributing to ISP reliability and preventing emails from ending in spam folders. You need to examine your mailing list periodically with a mailing tool to filter out the emails that bounce back, are invalid, have unsubscribed, or haven't engaged for over 12 months.

If you don't filter your mailing list, there is a high chance you'll be marked as spam and receive negative engagement metrics, which hinders your ISP credibility, slows the warming process, and lessens your email open rates.

You can manage these emails by creating suppression lists. You should only send emails to recipients who have opted in.

4. Limit your IP Addresses for Optimum Open Rates

Since warming one IP address takes effort, you may wonder if having multiple can help you send more emails to get a higher open rate. Having multiple IP addresses is not recommended because if ISPs catch you, they'll block all of them, and it's more than possible to send between two million and five million emails with one IP address.

You can use more than one IP address if you have multiple message streams, for example, dividing marketing and transactional emails. Still, keeping IPs to a minimum is best to avoid looking suspicious to ISPs. You'll gain more email open rates from one credible IP address than multiple weak ones.

5. Expect IP Warming to Decrease Open Rates

In the beginning stages of IP warming, it is typical for Gmail, Yahoo, Outlook, Comcast, and AOL to take longer for inbox deliveries or show bounces and will take a few rounds of emailing to clear up. Some mailing providers send mail directly to spam folders to see if the recipient will unmark the spam status. 

Remember that the process will take longer if you do a weekly IP warmup instead of a daily one. You might also run into other email delivery issues because your IP is still building a reputation. Your open rates will gradually increase as your email capacity does.

6. Create Quality Content When IP Warming

IP warming may seem like sending as many emails as possible, but your email quality is just as important, if not more. Quality content will lead to more open rates and engagement while increasing your ISP reputation.

Your content needs appealing subject lines and relevant subject matter that will make the recipients want to open the email and involve themselves with the business. By tailoring your emails, you'll avoid being marked as spam and speed up IP warming progression. (Related article: How to Keep Your Marketing Emails Out of the Spam Box)

7. Avoid Spam Traps

Spam traps use up your email spend and are dead ends, resulting in no open rates and a decrease in your ISP standing. There are Pristine, and Recycled spam traps that you need to be aware of:

  • Pristine spam traps are emails made to capture spammers and not by an actual person. Pristine traps show you have a corrupt data partner or weak list acquisition systems.
  • Recycled spam traps are emails previously owned by someone but became spam traps due to lack of use or disposal. Only after 6 or 12 months will it show you an error message, so make sure to have a good email filter to weed them out.

8. Make Use of Authentication Protocols

You must authenticate your IP address with email providers before you warm it and prevent your emails from being blocked or spammed. It would help if you verified your IP with your Sender ID records and Sender Policy Framework (SPF).

Furthermore, you must register with the correct DomainKeys Identified Mail (DKIM) and use CNAME to map your hostname. requires you to list your IP address on Microsoft's Smart Network Data Service (SNDS) if you intend to send a large volume of emails.

Final Thoughts

Sales ops reps must focus on setting realistic goals, streamlining the sales process, and seeking ways to improve to help salespeople. Having the right leadership, adopting the right tools, and implementing the right accountability system are the keys to ensure no opportunity is overlooked in sales.

About the Author

I have been in the 'online business' space since 2009 when I started an eCommerce business selling motorcycle parts (sold in 2012). Since then I have owned and operated several successful online business (and had a fair share of failures), along with owning offline home services businesses. Currently my focus is online businesses that are profitable with paid traffic. As a 'self employed individual' I do not use Linkedin, but you can connect with my on my personal instagram and youtube which largely revolve around my mountain biking passion!