What are the downsides of migrating from a shared IP to a dedicated IP for low volume email senders?
Matthew Whittaker
Co-founder & CTO, Suped
Published 6 Jul 2025
Updated 16 Aug 2025
7 min read
When considering email infrastructure, the idea of a dedicated IP address often sounds like the ultimate solution for better control and reputation. It is a common thought that having your own unique IP would automatically lead to superior email deliverability, especially if you have experienced issues on a shared IP.
However, for those of us sending low volumes of email, the reality can be quite different. What appears to be an upgrade can introduce a unique set of challenges and complexities that shared IPs often mitigate. It is important to understand these potential downsides before making the switch.
The challenges of IP warming and reputation building
One of the most significant hurdles for low-volume senders moving to a dedicated IP is the crucial process of IP warming. Email service providers (ESPs) and mailbox providers like Google and Microsoft look for consistent sending volume and good engagement from an IP address to build trust. Without this consistent volume, the IP remains "cold" and untrusted.
If you are only sending a few thousand emails per month, as many low-volume senders are, it becomes incredibly difficult to send enough mail consistently to properly warm up a new dedicated IP. Inconsistent or low volume can actually hurt your sender score, affecting deliverability, as noted by Klaviyo.
The cold start problem
Migrating to a dedicated IP with low email volume can result in unpredictable deliverability performance with inbox providers. It can take a long time to establish a reputation, and without sufficient daily volume, your new IP may struggle to build the necessary trust.
The direct consequence of an inadequately warmed IP is poor inbox placement. Your emails are much more likely to land in the spam folder or be blocked outright, even if your content is legitimate and your recipient list is clean. This negates the very reason most people consider a dedicated IP in the first place, leading to frustrating deliverability issues.
Unlike shared IPs, where your volume is blended with many other senders, allowing for a collective warming effect, a dedicated IP places the entire warming burden solely on your shoulders. For a more in-depth look at this, you can read about dedicated IPs and low volume email senders.
Increased responsibility and risk management
With a dedicated IP, you become the sole determinant of its reputation. On a shared IP, the reputation is influenced by all senders using it, meaning a well-managed shared pool can actually benefit lower-volume senders by leveraging the collective good sending habits. However, with a dedicated IP, any mistakes you make, such as sending to unengaged lists, hitting spam traps, or generating high complaint rates, directly impact only your IP.
Even a one-time error, such as messaging too many invalid email addresses or sharing poor content, can have significant and lasting consequences on your dedicated IP's reputation. Recovering from a tarnished reputation on a dedicated IP can be a lengthy and challenging process, requiring diligent effort to re-establish trust with mailbox providers.
Reputation management
Your IP's reputation is managed collectively by all senders on the shared pool. This can be beneficial for low-volume senders as the overall high volume helps maintain a consistent reputation.
Risk exposure
While poor sender reputation from one user can impact others, shared IPs offer some insulation. Minor mistakes might be absorbed by the larger sending volume, as described in the pros and cons of shared IP.
Reputation management
Your dedicated IP's reputation is entirely your responsibility. Every email you send contributes directly to its standing with mailbox providers.
Risk exposure
Any error or poor sending practice, no matter how small, can directly and severely impact your IP's deliverability, potentially leading to immediate blocklistings (or blacklistings) or filtering.
This increased responsibility also means you must actively monitor your IP's reputation. You will need to regularly check for blacklistings (or blocklistings) and proactively address any issues that arise. This level of continuous vigilance is often more demanding than what a low-volume sender typically needs or expects from their email infrastructure. Learning more about blocklist monitoring is crucial.
For very low volume transactional emails on a dedicated IP, these deliverability issues can be particularly challenging to address effectively without consistent volume to build and maintain trust.
Cost and technical considerations
Dedicated IPs generally come with a higher cost compared to shared IP options. This increased expense might not be justifiable for businesses or individuals with very low email volumes, where the potential benefits often do not outweigh the additional financial outlay. Shared IPs are typically included as part of a standard email service, making them more practical for smaller operations.
Furthermore, managing a dedicated IP often requires a greater level of technical expertise. While some email service providers abstract much of this complexity, you might still need a deeper understanding of DNS records like SPF and DKIM and how they interact with your sending IP.
DKIM and IP addresses
While Salesforce support might suggest a dedicated IP for 2048-bit DKIM keys due to their internal systems, DKIM (DomainKeys Identified Mail) is primarily a domain-based authentication method. It verifies that an email was authorized by the domain owner. The connection to the sending IP is typically indirect, relating more to how the ESP manages your specific DNS records and configurations based on your chosen IP infrastructure.
The original query mentioned migrating for a 2048-bit DKIM key, which, while a good security practice, does not inherently necessitate a dedicated IP. This is especially true given that the Salesforce support's stance on 2048-bit DKIM keys for shared IPs, highlighting risks like needing to "keep a watch on it" for IP changes, points to a provider-specific policy rather than a universal technical requirement.
It is critical to evaluate if the perceived ease of changing a DKIM key length truly warrants the numerous challenges associated with managing a dedicated IP for low volume. Often, a conversation with your email service provider about their specific DKIM management policies for shared IPs can reveal alternative solutions that do not require an IP migration.
Why shared IPs are often better for low volume
For senders with low volume, inconsistent sending patterns, or those just starting out, a shared IP address generally provides better deliverability. The high aggregate volume and diverse sending habits of other users on the shared IP help keep it "warm" and maintain a positive reputation with mailbox providers. This cushions individual senders from the severe impact of their own low or fluctuating volume.
Shared IPs simplify email sending significantly. You do not have to worry about the complexities of IP warming, reputation management, or constantly monitoring your IP's status on various blocklists (or blacklists). The provider handles these aspects, allowing you to focus on your email content and audience engagement.
Views from the trenches
Best practices
Maintain a steady email sending cadence to keep your IP warm and trusted.
Regularly clean your email lists to remove inactive or invalid addresses, reducing bounces and complaints.
Prioritize sending relevant content to engaged subscribers to build a positive sender reputation.
Common pitfalls
Moving to a dedicated IP with low sending volume, making it hard to warm the IP.
Sporadic email campaigns on a dedicated IP can damage its reputation.
High bounce rates, especially from unknown users, negatively impact IP reputation.
Expert tips
If your provider suggests a dedicated IP for DKIM key length, push back or seek clarification. DKIM is domain-based, not IP-based.
Ask your email service provider for details on their shared IP management and deliverability practices.
If high volume is achieved, look into IP certification programs for added deliverability benefits.
Marketer view
Marketer from Email Geeks says they strongly recommend against a dedicated IP with low email volume because it is difficult to establish a sending reputation.
2022-09-16 - Email Geeks
Marketer view
Marketer from Email Geeks says that having certified senders who send less than the queried volume indicates that good deliverability is possible, and questioned if the dedicated IP move was solely for authentication or due to existing deliverability issues.
2022-09-16 - Email Geeks
Making the right choice for your email sending
For low-volume email senders, the allure of a dedicated IP often masks significant downsides. The necessity of maintaining consistent high volume for IP warming, the increased responsibility for reputation management, and potentially higher costs or technical demands make it a challenging proposition.
While specific provider policies, such as those related to DKIM key lengths, might push you towards a dedicated IP, it is crucial to question if these are truly technical necessities or merely a simpler path from the provider's perspective. Your emails' performance, including open rates, can drop significantly if the IP is not warmed properly, as seen with dedicated IP migration issues.
Google and 
Microsoft look for consistent sending volume and good engagement from an IP address to build trust. Without this consistent volume, the IP remains "cold" and untrusted.
Salesforce support might suggest a dedicated IP for 2048-bit DKIM keys due to their internal systems, DKIM (DomainKeys Identified Mail) is primarily a domain-based authentication method. It verifies that an email was authorized by the domain owner. The connection to the sending IP is typically indirect, relating more to how the ESP manages your specific DNS records and configurations based on your chosen IP infrastructure.
