What deliverability improvement can be expected from using dedicated vs shared IPs?
Michael Ko
Co-founder & CEO, Suped
Published 4 Aug 2025
Updated 16 Aug 2025
7 min read
When we talk about email deliverability, one of the most frequent questions that comes up is whether to use dedicated or shared IP addresses. It's a common dilemma, especially for those sending significant volumes of email.
A shared IP address means your emails are sent from an IP address that is also used by other senders. Think of it like a public road, where many cars (emails) travel together. A dedicated IP address, on the other hand, is exclusively yours. This is like having your own private lane, giving you complete control over your sending reputation.
The choice between the two can significantly impact your inbox placement and overall deliverability. There isn't a one-size-fits-all answer, as the expected improvement depends heavily on your specific sending practices, volume, and how well you manage your email program.
Understanding IP reputation and control
The core of email deliverability often boils down to IP reputation. This is how internet service providers (ISPs) like Gmail and Yahoo perceive your sending practices. A good reputation means your emails are more likely to land in the inbox, while a poor one can send them straight to the spam folder or lead to them being blocked altogether.
With shared IPs, your reputation is influenced by everyone else on that IP. If another sender on the same IP engages in risky practices, like sending to old lists or getting high spam complaints, it can negatively affect your deliverability, even if your own sending habits are impeccable. Conversely, a shared IP with many reputable senders can offer a baseline of good deliverability, especially for new or low-volume senders, as the collective positive reputation lifts all boats. However, if you are not seeing mail from IP blocked messages, then simply moving to a dedicated IP might not change anything.
A dedicated IP, on the other hand, gives you full control. Your sending reputation is solely based on your actions. This means you have the power to build a strong, consistent reputation, but it also means you bear full responsibility for any issues. There is no existing reputation to lean on, and every sending decision directly impacts your deliverability. This can be both a blessing and a curse.
Shared IP
Reputation influenced: Your sending reputation is a collective score, impacted by all other senders using the same IP address. Good senders can help; bad senders can hurt. Understanding IP reputation is key.
Control: You have less direct control over the IP's overall standing, as it's shared among multiple users. You inherit the existing reputation.
Warming: Generally, no IP warming is needed since the pool is already established and warmed up by other senders.
Dedicated IP
Reputation built: Your reputation is built solely on your email sending behavior and practices. You control your destiny, for better or worse.
Warming: Requires a strategic IP warming process to build a positive reputation with ISPs gradually.
When dedicated IPs offer an advantage
A dedicated IP often makes sense when you're sending high volumes of email consistently. If you're sending millions of emails a month, a dedicated IP allows you to establish a robust and independent sending reputation. This can lead to more consistent delivery rates because ISPs are better able to identify and trust your specific sending patterns, rather than lumping you in with a shared group.
Furthermore, a dedicated IP can significantly reduce the risk of being affected by other senders' poor practices. If your shared IP neighbor gets blacklisted (or blocklisted), your emails might suffer too. With a dedicated IP, you isolate yourself from these external risks, making your deliverability more predictable and stable. This improves email deliverability if your sending practices are solid.
However, obtaining a dedicated IP isn't a simple flip of a switch. It requires a proper IP warming strategy, which means gradually increasing your sending volume over time to build trust with ISPs. This warming phase can sometimes lead to a temporary dip in inbox placement as the new IP gains reputation. Moving to a dedicated IP is a project that needs to be managed carefully.
Dedicated IP warming best practices
Start small: Begin with low email volumes and gradually increase over several weeks or months. Maintain good sending practices.
Segment audience: Send to your most engaged subscribers first, as positive interactions help build reputation faster.
Monitor closely: Keep a close eye on deliverability metrics, including open rates, click-through rates, bounces, and complaints.
Consistency is key: Maintain a regular sending schedule to demonstrate consistent, positive sending behavior to ISPs.
When shared IPs are often sufficient (or even better)
While dedicated IPs offer control, shared IPs are not inherently bad and are often the optimal choice for many senders. For businesses that send lower volumes of email, or send infrequently, a shared IP can be highly beneficial. In these scenarios, maintaining a dedicated IP's reputation with insufficient volume can be challenging, as ISPs prefer consistent sending from a specific IP to build trust.
A good email service provider (ESP) will manage their shared IP pools diligently, ensuring that other senders maintain good practices. This means you can often benefit from a pre-warmed IP with an established positive reputation, allowing you to start sending effectively right away without the overhead of IP warming. Shared IPs are a good choice for small businesses or those just starting out.
The deliverability improvement with shared IPs comes from leveraging the collective positive behavior of a large pool of senders. If your sending volume is inconsistent, or if you don't send enough to maintain a dedicated IP's reputation, a well-managed shared pool can actually provide better and more stable deliverability than a dedicated one. This is because the shared pool's reputation is constantly being reinforced by multiple good senders.
Factor
Shared IP Suitability
Dedicated IP Suitability
Email volume
Low to moderate, inconsistent sending (e.g., a few hundred to thousands a month).
Solely dependent on your sending. Higher risk from your own mistakes. Monitor blocklist status.
Cost
Usually included in your ESP plan, lower overall cost.
Additional cost, requires more management resources.
The role of sender practices
It's crucial to understand that neither a dedicated IP nor a shared IP is a magic bullet for deliverability. The biggest factor influencing whether your emails reach the inbox is your sender reputation, which is primarily built on your sending practices, not solely on your IP type.
Factors like list hygiene, email content quality, engagement rates, and proper email authentication (SPF, DKIM, DMARC) play a far more significant role. If you have poor list quality, high spam complaint rates, or send irrelevant content, a dedicated IP won't save you from the spam folder. In fact, it might even accelerate negative reputation building because all negative signals will be attributed directly to your single IP.
Before considering a dedicated IP, ensure your foundational deliverability practices are solid. Regularly clean your email lists, send engaging and desired content, and pay attention to bounce and complaint rates. Use tools like Google Postmaster Tools to monitor your IP and domain reputation. If these are good on a shared IP, the deliverability improvement from switching might be marginal.
Common pitfalls to avoid
Ignoring authentication: Failing to set up SPF, DKIM, and DMARC will hinder deliverability regardless of IP type.
Poor list hygiene: Sending to unengaged or invalid email addresses leads to bounces and spam traps, damaging reputation. Spam traps are a serious threat.
Maintain strong list hygiene by regularly removing inactive or bounced email addresses.
Consistently send high-quality, engaging content that your subscribers genuinely want to receive.
Actively monitor your sender reputation using tools like Google Postmaster Tools for insights.
Implement and maintain robust email authentication: SPF, DKIM, and DMARC are crucial.
Be prepared to manage the IP warming process meticulously if transitioning to dedicated IPs.
Common pitfalls
Assuming a dedicated IP will solve existing deliverability issues without addressing root causes.
Neglecting to warm up a new dedicated IP properly, leading to initial deliverability drops.
Sending inconsistent volumes on a dedicated IP, which can negatively impact its reputation.
Ignoring spam complaints and bounce rates, which are critical signals to ISPs.
Not having a clear strategy for managing your sender reputation, whether on shared or dedicated IPs.
Expert tips
For very high volumes or specific compliance needs, consider multiple dedicated IPs for different email streams.
Analyze your email program's specific needs, not just volume, when deciding on IP type.
Understand that deliverability is a continuous effort, not a set-it-and-forget-it task.
Leverage shared IP benefits for lower volume sends or during initial testing phases.
Focus on domain reputation as much as, or even more than, IP reputation, especially for modern ISPs.
Expert view
Expert from Email Geeks says that a dedicated IP does not guarantee a fix for existing deliverability problems. Most issues are related to sender actions, not the shared IP pool.
2022-03-16 - Email Geeks
Marketer view
Marketer from Email Geeks says if you are not seeing 'mail from IP blocked' messages, then moving to a dedicated IP will not change anything.
2022-03-16 - Email Geeks
Finding the right balance
Ultimately, the decision to use a dedicated versus a shared IP address comes down to a careful evaluation of your specific email program. There's no inherent 'better' option, but rather a strategic choice that aligns with your sending volume, consistency, and overall deliverability goals. Choosing the right IP is a critical step.
For high-volume, consistent senders who prioritize maximum control and predictability, a dedicated IP, if managed correctly, can offer significant deliverability improvements and risk mitigation. For lower-volume or inconsistent senders, a well-managed shared IP often provides sufficient, and sometimes superior, deliverability without the complexities of IP warming and ongoing reputation management. Always remember that strong sender practices are the bedrock of good deliverability, regardless of your IP choice.
Gmail and 
Yahoo perceive your sending practices. A good reputation means your emails are more likely to land in the inbox, while a poor one can send them straight to the spam folder or lead to them being blocked altogether.
