IP Address

Email Service Providers (ESPs) and marketing automation organizations often provide a sender two options when it comes to the IP address they will be sending email from: a shared IP address or a dedicated IP address. Which one is better for your email marketing sending? Before we dive into this discussion, let’s cover the basics.


What is an IP address?

An Internet Protocol address (IP address) is a numerical number assigned to any device connected to the Internet – your PC, tablet, or smartphone, your Nest thermostat, your refrigerator, your Whistle GPS pet tracker, and so on. The purpose of this address is to identify different devices and the user/host. Your IP address allows the Internet, websites, Internet service providers, and servers to identify you.

What’s the difference between dedicated and shared IP addresses?

Just as their names imply, a “dedicated IP address” is one that is dedicated to the use of a single company, while a shared IP address is one that’s used by multiple companies. The number of companies sharing the same IP address can vary dramatically from a few to several thousand. Depending on what?

Benefits and drawbacks of shared IPs

Certain Types of Senders Should Consider a Shared IP

Shared IP addresses have advantages that will entice some senders to choose this option over a dedicated IP address. Since you are sharing IPs with other senders, your sending reputation is aggregated. For low-volume senders, this will definitely be beneficial; you will be able to piggy-back off other sender’s reputations and consequently establish a sending reputation.

Seasonal senders should seriously consider a shared IP as well. If you have inconsistent sending volume, you’d need to warm up a dedicated IP address every year. With a shared IP there is no need to worry about that. Your volume will be combined with the other senders on the shared IP, which generally has a pretty consistent sending volume ­– so no red flags to receiving servers.

A Shared IP is Less Expensive

Using a shared IP address costs less than a dedicated one. For small businesses and low-volume senders, the cost of a dedicated IP may not be a practical (or necessary) expenditure for their email marketing budgets.


The fact that sending reputation is shared among the senders of a shared IP can be beneficial, but for some senders it could be a drawback.

The senders with great sending habits and who adopt industry best practices experience a consistent medium or high volume are the ones raising the average of the sender reputation on the shared IPs. These senders may be put in the position of “taking one for the team,” though, if the others on the shared IP are inconsistent senders, or have poor list management practices. If you’re a sender with the less-than-stellar sending habits, find out what you can do to improve your own practices so you don’t negatively affect the group.

Benefits and drawbacks of Dedicated IPs

Types of Senders

The main reason for moving to a dedicated IP address is to control your own reputation. The senders most eligible for a dedicated IP would be the consistent medium- to high-volume senders. I’m not saying low-volume senders cannot opt for a dedicated IP as well; it’s just that in terms of improving your reputation, a low-volume senders may not see as large of an increase, as a medium- or high-volume sender.

MY IP Address

Since you are the only sender sending from a dedicated IP, you have more control over your reputation – and more accountability. Having more control over their sending reputation often leads to better delivery and inbox placement – that is, if you do your part and have good sending habits. If your email marketing team is diligent and well versed in email marketing and compliance this should not be an issue for you.

Another benefit of having a dedicated IP is the monitoring and tools that can give you better insight on your deliverability. With a dedicated IP, since you aren’t aggregated with other senders, you can use tools such as 250ok, Retun Path, Microsoft SNDS, and various other tools to measure metrics around blacklists, spam traps, spam complaints, inbox placement, and to help in assessing the overall success of your IP address and sender reputation.


Cost is a factor to consider when choosing between the two IP options. Dedicated IPs generally cost more. Dedicated IPs will generally require more work and maintenance, but most of this occurs in the early stages as you warm up a new IP address. This requires you to gradually increase your sending volume over a period of time, and to pay particular attention to how you segment your lists. This warm up is mandatory in order to start off with a good sending reputation. Without a warm up internet service providers (ISPs) will see a large spike in volume from a new IP address, which is usually a red flag telling them this IP address is most likely a spammer or botnet.

When you transition from one email service provider to another

Moving between ESPs happens for many reasons including better technology options and integration solutions. You should, however, expect a transition period once you make the move as it takes tiome to reestablish your digital reputation after the transation.

A few things to consider are:

Is your volume holding high and steady? If you decide to move to a dedicated IP address at the same time as you change ESPs, you’ll need to go through the same warming process as described above.

If you’ve been on a shared IP address and plan to stay on one, you‘ve got different considerations. You’ve probably been paying ongoing attention to list hygiene and validation; don’t slack off now. In addition, look closely at:

  • The reputation of your content
  • The reputation of your partners (via the links in your emails)
  • Your formatting (such as image-to-text ratio)
  • What has not worked well in the past

Weigh the advantages and disadvantages and from there you can make a decision which will be most beneficial for your email marketing sending.


Both options have their advantages and disadvantages. Take some time and analyze what kind of sender you are. Be completely honest with yourself about your email practices. If you’re not completely confident about your sending habits, then it’s very possible that you’ll benefit from the good habits of other senders on a shared IP. You can always grow into a dedicated IP later.

The art of successful email marketing depends first and last upon proactive deliverability management. This eBook will help you manage the critical factors that affect the deliverability of your email messages.

Best Practices in Email Deliverability