TL;DR:
- The right choice depends on your email volume, consistency, and ability to manage deliverability best practices.
- Dedicated IPs give you full control over your sender reputation—but require high volume, strong practices, and time to warm up.
- Shared IPs are easier, cheaper, and better for low-volume senders—but your reputation is influenced by others.
Introduction
Choosing between a dedicated IP vs shared IP isn’t just a technical decision—it can directly impact your email deliverability, sender reputation, and overall marketing performance. Yet many marketers make this choice without fully understanding the trade-offs. In this two-part series, we break down how shared and dedicated IPs work, along with their advantages and drawbacks, so you can confidently choose the setup that aligns with your email volume, resources, and long-term strategy.
What is an IP address?
An IP address is an exclusive number online that services and devices use to identify you. Think of it as a mailing address. You might have your own dedicated address (as, say, your home address) and you might also have a shared address (as, say, an office address).
Your email service provider (ESP) – hosts email marketing services on its servers. It could be a stand-alone email service provider, or it could be one part of an integrated marketing automation provider (such as Act-On), which surrounds your email with complementary services. Either way, along with choosing a provider that best suits your marketing and sales teams’ needs, it is also important to have the right infrastructure behind the service. Many email service providers will automatically apply the infrastructure that’s suited to their own objectives, but others give you the option to decide. This series will help you to identify which one is best for your company.
Dedicated IP explained
A Dedicated IP is a great way for email marketers to build and maintain their own IP and domain reputation. Also, having a dedicated IP lets marketers control more of their own deliverability destiny in the email-marketing ecosystem. No other senders can negatively influence the effectiveness of your marking initiatives.
Many clients love this idea, but for others it does become the ‘moment of truth’– and the truth can hurt. If you’re in a shared IP pool in which other senders have more compliant sending habits than you do, then their good reputation is giving yours an assist. Moving to a dedicated IP may reveal just how much help the shared pool was. Getting a dedicated IP gives marketers the ownership of which direction the IP will take … either positive or negative.
Pros of Dedicated IPs
- A dedicated IP address allows you to totally control your own sending destiny as an email marketer.
- Your sending reputation will be affected by only the choices you make as a marketer. If you have excellent sending and data management practices, this is generally the best way to send emails.
- A dedicated IP gives you more control over your email sending reputation and in return can give you better delivery rates – if warmed properly and maintaining a consistent sending management plan.
- A dedicated IP is useful if you frequently must request white listing of your IP. Many high security industries look for dedicated IPs; so if you’re selling to a high security industry of any kind, dedicated IPs can help you get through specific filters.
Cons of Dedicated IPs
- Not good for low volume. If you are not sending at least 200K emails per month, it’s going to be hard to maintain a good, trustworthy reputation with ISPs.
- You could become your own worst enemy. As with shared IPs, you get the benefit of other senders. On dedicated IPs all success comes only from you. If you’re not following best practices – this could hurt you.
- The IP address must be warmed up. Your new dedicated IP address will be “cold,” you’ll need to warm it with your company’s sending practices to establish and maintain a good reputation with ISPs. The ramp up time takes 45-60 days on average and cannot be rushed.
- Higher cost for dedicated IPs. It costs email service providers a lot of money to procure and maintain IPs for customer use, and so they protect the revenue they get for dedicated IPs. By locking into a dedicated IP, you have made the decision to be in a long-term relationship; you can’t buy one, then burn and turn it if it doesn’t go as expected.
All that said, if you send high volumes of email on a very frequent basis, you should consider a dedicated IP. If you make the switch, make a concurrent commitment to best practices in regards to list hygiene and relevancy of content.
Shared IP Explained
A shared IP is an IP that is used by several other companies or senders. For a real-world example, imagine a shared office space in which six companies have spaces there, and all use this address: The Sloan Building, 1234 Washington St., Chicago Illinois, 60202.
ESPs typically have several pools of shared IPs, which allows them to distribute volume across the pools. Each pool holds the appropriate number of mailing contacts for IPs to handle the volume going off of them at any single moment. The placement of pools is managed on the back end by engagement metrics, such as complaint rates, bounce rates, and open and click rates. Any fluctuation in these metrics on the pools can positively or negatively affect your sending practices.
Pros of Shared IPs
- Volume is already established and consistent. This means you don’t have to work through a “warming up” period in which receiving ISPs (such as Gmail and company ISPs) must learn to differentiate your IP from spammers. They already know the address you are sending from is established, proven, and good, so it’s far more likely that your mail will be received (all other things being equal). So, you are able to easily and quickly get your mailings out without worrying about establishing a consistent volume with the ISPs.
- Get help from other senders. With a shared pool, you are sending with other senders and therefore their metrics and engagement numbers can help your marketing initiatives.
- Cost is relatively low. The costs to maintain shared IPs are lower than to maintain dedicated IPs.
Cons of Shared IPs
- Risk of some loss of brand and reputation at email sending level. When using a shared IP pool environment, your sending brand integrity is merged with all the other brands; true reputation can only be established at the ESP and IP level, not at your brand/domain level.
- Negative help from senders. Just as your sending reputation is enhanced when others in the pool follow best practices, there could be a negative impact on the IP address (and on your sending reputation) if other senders in your pool implement less than ideal practices. That said, ESPs that manage pools are careful to monitor sending practices, for everyone’s benefit.
Shared IP pools are particularly good for companies that send on a irregular basis and or don’t have a large list of recipients. In both those cases, ISPs will not have the history of interacting with you to apply high levels of trust.
Shared IP pools are also great for companies that are just launching, or just starting email marketing, for the same reasons: With a IP pool, you’ll be using a known and trusted address.
For more information on deliverability, check out the Best Practices in Email Deliverability.