Summary
When migrating Email Service Providers (ESPs) with an engaged B2B email list to a new shared IP, the consensus among experts is that some form of gradual volume ramp-up or 'warmup' is generally necessary, or at least highly advisable. While shared IP pools manage collective reputation, Internet Service Providers (ISPs) still observe how your specific sending domain behaves from the new IP addresses. B2B recipients, in particular, often have stricter spam filters that are sensitive to changes in sending patterns. Although a highly engaged list is a significant advantage, a sudden shift in sending infrastructure can still trigger monitoring or filtering, making a measured approach crucial to maintaining strong deliverability and preventing initial issues.
Key findings
- Ramp-up is Prudent: The majority of email marketing experts and ESP documentation recommend a gradual increase in sending volume, or a 'ramp-up,' even when using shared IPs and possessing an engaged B2B list.
- Domain Reputation on New IPs: The primary reason for a ramp-up is to establish or re-establish your specific domain's sending reputation with ISPs from the new IP ranges. ISPs observe your domain's behavior on the new infrastructure.
- B2B Specific Challenges: B2B lists face stricter corporate spam filters and firewalls, which are highly sensitive to new sending patterns and sources, necessitating a cautious introduction of your traffic from the new ESP.
- Engaged List is an Asset: While an engaged B2B list is a major advantage that can mitigate some risks, it does not entirely eliminate the need for a strategic ramp-up, as ISPs still need to build trust with your domain on the new sending infrastructure.
- Shared IP Nuances: Even though shared IPs collectively manage reputation, your individual sender practices and list quality still influence your deliverability within that shared pool, requiring a mindful transition.
Key considerations
- Start with Engaged Segments: Initiate sending to your most engaged audience segments first, gradually expanding to broader portions of your list as deliverability proves stable.
- Monitor Deliverability Closely: Continuously monitor bounces, complaints, and overall deliverability rates during the initial campaigns to identify and address any potential issues promptly.
- Spread Out Initial Campaigns: Avoid sending large volumes in a single burst. Instead, spread out your first few campaigns over a period to allow ISPs to observe consistent good sending behavior.
- Verify Authentication: Ensure proper self-DKIM authentication and other SPF, DMARC records are correctly configured for your domain with the new ESP before sending.
- Consult ESP Guidance: Adhere to the specific sending ramp-up recommendations provided by your new ESP, as they often have guidelines tailored to their shared IP environments.
What email marketers say
9 marketer opinions
While moving an engaged B2B email list to a new Email Service Provider (ESP) on a shared IP might seem to lessen the need for IP warmup, most email marketing experts advise a deliberate, gradual increase in sending volume. Receiving Internet Service Providers (ISPs), particularly those serving B2B recipients, are sensitive to sudden changes. They observe your domain's sending patterns from the new IP ranges, and even with a reputable shared IP, your specific volume needs to be introduced cautiously to build trust and prevent filtering. An engaged list is a significant asset, yet a measured approach ensures continued strong deliverability and minimizes initial deliverability shocks as your domain establishes its reputation with the new sending infrastructure.
Key opinions
- Ramp-Up is Highly Advisable: Despite using a shared IP and having an engaged B2B list, the majority of experts recommend some form of gradual volume ramp-up when moving Email Service Providers.
- Domain Reputation Shifts: The transition primarily involves establishing or reinforcing your domain's sending reputation from the new set of IP addresses, as ISPs recognize your domain sending from a different source.
- B2B Filters Are Sensitive: B2B environments often have stricter corporate spam filters and firewalls that are particularly sensitive to changes in sending patterns, necessitating a cautious approach.
- Engaged List is an Advantage: While an engaged list is a significant asset that can help mitigate risks, it does not entirely eliminate the need for a strategic, measured ramp-up period.
- ISPs Learn New Patterns: Receiving Internet Service Providers need time to observe and learn your domain's specific sending behavior and volume from the new ESP's infrastructure.
Key considerations
- Target Engaged Segments First: Start by sending to your most engaged audience segments. This helps establish positive sending reputation quickly with the new IP ranges and infrastructure.
- Spread Out Initial Volumes: Avoid sending large volumes immediately. Instead, gradually increase your sending volume over time, allowing ISPs to acclimate to your domain's sending patterns from the new ESP.
- Monitor Deliverability Metrics: Closely track key metrics like bounces, complaints, open rates, and click-through rates during the transition phase to quickly identify and address any potential deliverability issues.
- Verify Authentication Records: Ensure that your domain's SPF, DKIM, and DMARC records are correctly configured and propagated with your new Email Service Provider prior to initiating sends.
- Consult ESP Specific Guidance: Adhere to any specific ramp-up or migration guidelines provided by your new ESP, as they have insights into their shared IP pools and infrastructure.
Marketer view
Email marketer from Email Geeks explains that there is a small chance of some bounces in the first campaign on such volume, depending on mailbox providers, but if the domain reputation is well-established, major problems are unlikely. He advises spreading out the first few campaigns and targeting the most engaged users first.
21 Sep 2024 - Email Geeks
Marketer view
Email marketer from Email Geeks explains that IP warmup is likely not needed if using a shared IP, maintaining proper self-DKIM authentication, and using the same domain.
13 Jun 2022 - Email Geeks
What the experts say
2 expert opinions
When migrating an engaged B2B list of approximately 8,000 recipients to a new Email Service Provider (ESP) on a shared IP, expert opinions vary regarding the absolute necessity of IP warmup. Some suggest that for lists of this size, particularly B2B, a full warmup might be bypassed, provided close monitoring of deliverability metrics. However, others firmly assert that any transition to new sending infrastructure, even shared IPs, mandates a gradual ramp-up of sending volume. This process allows Internet Service Providers (ISPs) to observe and build trust in your domain's behavior from the new IP addresses, a critical step for maintaining strong deliverability and reinforcing sender reputation.
Key opinions
- Divergent Views on Small Lists: One expert suggests that for an 8,000-recipient B2B list, IP warmup might not be strictly necessary, especially on a shared IP, emphasizing careful monitoring instead.
- Warmup is Generally Necessary: Another expert firmly states that IP warmup is essential for any move to new sending infrastructure, including shared IP pools at a new ESP, regardless of list engagement or type.
- ISPs Need Observation: The core reason for warmup is to allow Internet Service Providers to observe and build trust in your domain's sending patterns from the new IP addresses.
- Less Aggressive, Still Crucial: While warmup for shared IPs might be less aggressive than for dedicated IPs, it remains vital for establishing domain reputation and sender trust on the new infrastructure.
- Threshold for Warmup: One expert indicated a personal threshold for starting a warmup process at around 10,000 recipients, suggesting smaller lists might behave differently.
Key considerations
- Monitor Closely: Regardless of whether a full warmup is performed, actively monitor bounce rates, spam complaints, and overall deliverability metrics during the initial sending phases from the new ESP.
- List Size as a Factor: Consider the total size of your list, as some experts suggest a lower threshold (e.g., under 10K) might allow for less aggressive or no explicit warmup, particularly for engaged B2B lists.
- Prioritize Domain Reputation: The primary goal is to establish or reinforce your domain's sending reputation with ISPs on the new infrastructure. This process happens through consistent, good sending behavior, which a gradual ramp-up facilitates.
- Consult ESP Guidance: Always consult your new Email Service Provider for their specific recommendations, as they understand the nuances of their shared IP pools and how best to onboard new senders.
Expert view
Expert from Email Geeks explains that for a list of 8K, especially with B2B domains, IP warmup might not be necessary, suggesting it's likely okay but to monitor bounces. She notes that she often starts warmup at 10K recipients.
10 Feb 2024 - Email Geeks
Expert view
Expert from Word to the Wise explains that IP warmup is necessary when moving ESPs, even with an engaged B2B list on a shared IP. She states that any move to new sending infrastructure, including shared IP pools at a new ESP, requires a gradual ramp-up of sending volume. This process allows Internet Service Providers (ISPs) to observe and trust the sender's behavior from the new IP addresses. While the warming process may be less aggressive than for dedicated IPs, building domain reputation and sender trust on the new infrastructure is crucial for deliverability.
10 Feb 2024 - Word to the Wise
What the documentation says
5 technical articles
When transitioning an engaged B2B list to a new Email Service Provider (ESP) that utilizes shared IPs, the consensus among leading ESPs is that a form of gradual volume increase is highly beneficial. Although shared IP pools collectively manage reputation, Internet Service Providers (ISPs) still closely observe your specific sending domain's behavior from these new IP addresses. This careful ramp-up allows ISPs to re-establish trust with your domain on the new infrastructure, preventing potential deliverability issues, especially given the strict filters often encountered in B2B environments. An engaged list provides a strong foundation, but it does not bypass the need for a thoughtful transition to acclimatize receiving servers to the change in your sending origin.
Key findings
- Shared IP Nuance: While shared IP pools manage a collective reputation, individual sender behavior-specifically your domain's sending patterns-continues to significantly influence deliverability within that shared environment.
- Domain-IP Trust Building: ISPs need to re-establish trust with your specific sending domain as it begins sending from the new shared IP addresses, making a gradual introduction of volume crucial.
- B2B Filtering Sensitivity: B2B receiving servers often employ stricter filtering mechanisms that are particularly sensitive to sudden changes in sending infrastructure or volume from a known domain.
- Engaged List Still Needs Ramp-Up: Even with a highly engaged B2B list, the act of moving ESPs and therefore changing the sending IP infrastructure necessitates a gradual volume increase to ensure continued good deliverability.
- Preventing Initial Filtering: A cautious ramp-up helps prevent ISPs from misinterpreting a sudden surge in volume from your domain on a new IP as suspicious, thereby avoiding initial over-filtering or blocks.
Key considerations
- Gradual Volume Increase: Implement a structured plan to slowly increase your sending volume from the new ESP, allowing receiving servers to gradually adjust to your traffic patterns.
- Close Deliverability Monitoring: Diligently monitor key deliverability metrics, such as bounce rates, complaint rates, and engagement, to quickly identify and address any issues during the transition.
- Rebuild Domain Reputation: Focus on consistently demonstrating good sending practices from the new shared IP to re-establish and reinforce your domain's positive sending reputation with ISPs.
- Account for B2B Rigor: Tailor your ramp-up strategy to account for the stricter email filtering and security protocols commonly found within B2B recipient environments.
- Consult ESP Guidelines: Always refer to and follow the specific recommendations and best practices provided by your new Email Service Provider for onboarding and shared IP usage.
Technical article
Documentation from SendGrid Documentation explains that while shared IP pools are designed to manage reputation collectively, even with an engaged list, a sender's specific sending habits and list quality can still influence their individual deliverability within the shared pool. It's recommended to gradually increase sending volume, especially when migrating, to allow ISPs to re-establish trust with the sender's specific traffic patterns on the new shared IP.
18 Sep 2021 - SendGrid Documentation
Technical article
Documentation from Mailchimp Knowledge Base explains that Mailchimp manages the reputation of its shared IPs. While individual IP warmup isn't explicitly required by users on shared IPs, they advise that a good sender reputation, built on consistent engagement and low complaint rates, is paramount. When moving, the list's health dictates much of your initial success; however, a sudden high volume from a 'new' source (your domain via Mailchimp's shared IP) could still trigger monitoring, making a gradual transition beneficial for the B2B context.
8 Jan 2024 - Mailchimp Knowledge Base
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