How to warm up a dedicated IP without interrupting existing email campaigns?
Matthew Whittaker
Co-founder & CTO, Suped
Published 26 May 2025
Updated 19 Aug 2025
8 min read
Moving to a dedicated IP address is a significant step towards greater control over your email deliverability and sender reputation. However, the critical process of IP warming often raises a key question: how do you warm up this new IP without disrupting your ongoing, business-as-usual (BAU) email campaigns? Halting regular communications for weeks is rarely an option for most businesses. The goal is to build trust with internet service providers (ISPs) for your new dedicated IP, while ensuring your existing campaigns continue to reach their intended recipients without interruption or negative impact.
Understanding IP warming and its challenges
When you acquire a new dedicated IP address, it has no prior sending history, meaning it lacks a established sender reputation. ISPs are wary of new IPs that suddenly send large volumes of mail, as this behavior is often associated with spammers. To avoid being flagged as suspicious, you must gradually increase the volume of emails sent from the new IP over time. This process, known as IP warming, builds a positive sending history and reputation, signaling to ISPs that you are a legitimate sender.
The primary risk of not warming up an IP correctly is poor deliverability. If you start sending high volumes from a cold IP, your emails are likely to be filtered to spam folders, bounced, or even outright rejected by ISPs. This can lead to your IP address being placed on a blocklist (or blacklist), severely impacting your email program. Even if your emails don't get blocklisted, they might land in the junk folder, which is nearly as detrimental. We've seen this issue frequently, where a lack of proper warming leads to significant email deliverability issues down the line.
However, for businesses that rely on continuous email communication, pausing existing campaigns for a traditional 30-day (or longer) IP warming period is often impractical. Marketing, transactional, and operational emails are crucial for engagement and revenue. The challenge lies in strategically introducing the new IP to ISPs while keeping your established email flows running smoothly, without causing a dip in deliverability or damaging your domain reputation.
Strategic overlap and audience segmentation
The most effective approach to warm up a dedicated IP without disrupting ongoing campaigns is to implement a strategic overlap period. This involves using both your old (shared or existing dedicated) IP and your new dedicated IP simultaneously. During this period, your existing campaigns continue to be sent from the old IP, while your new IP begins to send a controlled volume of emails to your most engaged subscribers. This allows you to maintain business as usual (BAU) communications while slowly building the reputation of your new IP address.
A crucial component of this strategy is audience segmentation. You should initially send only to your most active and engaged subscribers from the new IP. These recipients are most likely to open, click, and interact positively with your emails, sending strong positive signals to ISPs. This helps to rapidly build a good reputation for the new IP. Meanwhile, less engaged segments or those with lower open rates can continue to receive emails from the old IP until the new IP is fully warmed.
Another common strategy, especially when moving to a new ESP or if your current ESP's infrastructure supports it, is to utilize a different subdomain for the new dedicated IP during the warmup phase. For example, your existing campaigns might use marketing.yourdomain.com, while the new IP warms up using warmup.yourdomain.com. Once the warming is complete, all traffic can be consolidated under the primary sending subdomain.
Using two IP addresses concurrently
During the warming phase, you maintain your primary sending volume from your established (old) IP address. Simultaneously, you begin to send a small, controlled volume of emails from your new dedicated IP. This parallel sending ensures that your BAU campaigns remain unaffected.
Audience management
Send only to your most engaged subscribers (e.g., those who have opened or clicked an email in the last 30-60 days) from the new IP. These positive interactions signal trustworthiness to ISPs, accelerating the reputation building process.
Maintaining reputation during the transition
While warming a dedicated IP, consistency is paramount. Maintaining a regular and consistent sending volume from the new IP, even if small, is more beneficial than sporadic bursts. ISPs prefer predictable sending patterns, which builds trust over time. Avoid sudden, large jumps in volume, as this can trigger spam filters and lead to your IP being placed on a blocklist or (blacklist). Mailchimp also highlights the importance of gradual volume increases.
It's essential to monitor both your IP reputation and your domain reputation throughout the process. Tools like Google Postmaster Tools can provide valuable insights into your sending reputation, spam rate, and delivery errors. Pay close attention to feedback loops and bounce rates. High bounce rates or spam complaints from the new IP can quickly undermine your warming efforts. Remember, a good domain reputation can support a new IP, but a poor IP reputation will ultimately damage your domain's standing. You should be consistently monitoring for any potential blocklist (or blacklist) issues.
Before embarking on an IP warming journey, thoroughly understand your Email Service Provider's (ESP) capabilities. Some ESPs offer automated IP warming features or have specific guidelines for managing multiple IPs or subdomains during a transition. Others may require more manual configuration. Consulting with your ESP's support or deliverability team can save you significant time and effort, ensuring their system can accommodate your desired overlapping strategy. For instance, Microsoft Dynamics 365 Journeys offers guidance on their warm-up process.
Best practices for a smooth IP warm-up
Start small: Begin with a very small volume of emails to your most engaged subscribers on the new IP.
Gradual increase: Slowly increase the daily volume sent from the new IP over several weeks. A typical IP warming schedule might span 30-60 days.
Highly engaged lists: Prioritize sending to contacts who have recently opened or clicked your emails. These positive interactions are key.
Monitor closely: Keep a watchful eye on your bounce rates, spam complaints, and overall inbox placement. Adjust sending volume if you see negative trends or get added to a blocklist (or blacklist).
Implementation and monitoring strategies
Implementing a parallel sending setup often involves configuring your ESP to route specific campaigns or audience segments through the new IP. This might mean setting up new sending domains or subdomains for the dedicated IP, ensuring proper authentication records like SPF, DKIM, and DMARC are in place. Your ESP should be able to guide you through these technical configurations. For those considering a new ESP, understanding their IP warming process and capabilities is a crucial step.
Throughout the IP warming process, continuous monitoring of key metrics is non-negotiable. Pay close attention to your open rates, click-through rates, bounce rates (especially hard bounces), spam complaint rates, and unsubscribe rates specifically for the traffic sent via the new IP. A sudden increase in bounces or complaints indicates that you may be sending too much volume too quickly, or to less engaged recipients, and you should scale back. Monitoring your IP on various email blocklists (blacklists) is also essential.
Once your new dedicated IP has consistently shown strong performance over the recommended warming period, and your key metrics are stable and positive, you can gradually shift more of your email volume from the old IP to the new one. This transition should also be gradual, not a sudden cut-over. Continue to monitor performance closely during the final phases of migration to ensure a smooth and successful complete switch. For specific transactional email IP warm-up scenarios, different guidance may apply.
Sample IP warming schedule (example, not exhaustive)
Day 1: 500 emails to most engaged
Day 2: 1,000 emails
Day 3: 2,000 emails
Day 4: 4,000 emails
Day 5: 8,000 emails
Day 6: 16,000 emails
Day 7: 32,000 emails
...
Gradually increasing volume daily to target engaged subscribers.
Conclusion
Warming up a dedicated IP without disrupting existing campaigns is entirely feasible with careful planning and execution. The key is to run a parallel operation, leveraging your existing IP for BAU sends while methodically building the reputation of your new IP with your most engaged audience segments. This strategy minimizes risk, maintains deliverability, and ensures a smooth transition to your new sending infrastructure, ultimately leading to improved long-term inbox placement.
Views from the trenches
Best practices
Start by overlapping your old and new IP addresses for parallel sending.
Segment your audience, sending only to your most engaged subscribers on the new IP first.
Use a dedicated subdomain for the new IP during the warming phase if your ESP allows it.
Maintain consistent sending volumes and closely monitor your deliverability metrics.
Communicate with your ESP to understand their specific IP warming features and support.
Common pitfalls
Stopping all existing email campaigns to focus solely on warming the new IP.
Sending high volumes to unengaged lists from a cold IP, leading to immediate blocklisting (blacklisting).
Failing to monitor deliverability metrics and not reacting to negative trends.
Not understanding your ESP's capabilities for multi-IP management or subdomain usage.
Attempting to warm a new IP and domain simultaneously without a strategic plan.
Expert tips
Consider using transactional emails for initial warming, as they typically have high engagement.
Gradually increase the volume sent from the new IP, following a structured schedule.
Ensure all authentication records (SPF, DKIM, DMARC) are correctly configured for the new IP.
Prioritize sending highly personalized and valuable content from the new IP to encourage engagement.
If moving ESPs, manage the domain reputation carefully as it transfers with your sending domain.
Expert view
Expert from Email Geeks says the best solution is to overlap old and new IPs, using old IPs for business-as-usual communications and the new ones for highly engaged segments, transitioning slowly.
2019-12-17 - Email Geeks
Marketer view
Marketer from Email Geeks says they typically assign a new dedicated IP pool with a different subdomain for warmup, then shift all traffic to it once the warming is complete.
