Suped

Is a warm up period necessary when migrating to a new ESP with the same sending domain and address?

Summary

Experts, marketers, and documentation from various sources consistently recommend a warm-up period when migrating to a new ESP, even if the sending domain and address remain the same. The primary reason cited is the change in IP addresses associated with the new ESP. These new IPs require a reputation build-up to avoid triggering spam filters. The consensus advises gradually increasing sending volume, beginning with the most engaged users, while closely monitoring deliverability. Factors like DKIM, envelope domain, shared vs. dedicated IPs, and list quality influence the process.

Key findings

  • New IPs = New Reputation: Regardless of domain reputation, new IP addresses require a new reputation to be built with ISPs.
  • Gradual Volume is Critical: A gradual increase in sending volume is essential to avoid being flagged as spam and to establish a positive sending reputation.
  • Engagement Improves Deliverability: Starting with highly engaged users can positively influence the warm-up process and improve deliverability rates.
  • Warm-up Mitigates Risk: Failure to warm-up new IPs can severely impact deliverability and sender reputation.

Key considerations

  • Shared vs. Dedicated IPs: The warm-up process may be slightly faster with shared IPs, but it's still necessary.
  • Authentication Protocols: Ensure that SPF, DKIM, and DMARC records are properly configured with the new ESP.
  • List Quality: List quality and engagement metrics significantly influence the speed and success of IP warm-up.
  • Monitor Deliverability: Closely monitoring deliverability during the warm-up phase is crucial for identifying and addressing any issues.
  • Avoid Volume Spikes: Sudden increases in sending volume can negatively impact your sender reputation.

What email marketers say

10 marketer opinions

Experts and marketers overwhelmingly agree that a warm-up period is necessary when migrating to a new ESP, even if the sending domain and address remain the same. This is primarily due to the change in IP addresses associated with the new ESP, which requires building a new sending reputation with ISPs. The consensus is to gradually increase sending volume, starting with the most engaged users, while closely monitoring deliverability to avoid being flagged as spam.

Key opinions

  • IP Reputation: New IP addresses require building a new reputation with ISPs, even if the sending domain remains the same.
  • Gradual Warm-up: Gradually increasing sending volume is crucial for establishing a positive sending reputation.
  • Engagement Matters: Starting with the most engaged users during the warm-up process can improve deliverability.
  • Deliverability Monitoring: Closely monitoring deliverability throughout the warm-up period helps identify and address potential issues.
  • Risk Mitigation: Warming up is a way to mitigate risks to reputation when moving platforms.

Key considerations

  • IP Type: Whether you are using shared or dedicated IPs will affect the warm up schedule.
  • Engagement Rates: List quality and engagement rates influence the speed and success of the warm-up process.
  • Volume Spikes: Avoid sudden spikes in email volume, as they can negatively impact your sender reputation.
  • Authentication Protocols: Ensure proper setup and configuration of authentication protocols (SPF, DKIM, DMARC) with the new ESP.
  • List Segmentation: Segment your email list and prioritize sending to highly engaged subscribers during the initial warm-up phases.

Marketer view

Email marketer from Mailjet explains that even with the same sending domain, a warm-up period is necessary when migrating to a new ESP, particularly if using dedicated IPs. They recommend gradually increasing sending volume to build a positive reputation with ISPs.

30 Aug 2024 - Mailjet

Marketer view

Email marketer from GlockApps answers that IP warm-up is a process of gradually increasing the volume of emails sent from a new IP address. This is done to establish a good sending reputation with ISPs.

4 Oct 2024 - GlockApps

What the experts say

5 expert opinions

Experts agree that a warm-up period is necessary when migrating to a new ESP, even with the same sending domain and address. This is primarily due to the change in IP addresses, DKIM, and envelope domain associated with the new ESP. Although domain reputation can carry over, it's crucial to establish trust on the new IPs to avoid spam filters.

Key opinions

  • New IPs Require Warm-up: Regardless of domain reputation, new IP addresses need to be warmed up to establish trust with mailbox providers.
  • Technical Changes: Changes in IPs, DKIM, and envelope domains necessitate a warm-up period.
  • Aggressive Spam Filters: Sending from new IPs without a warm-up can trigger aggressive spam filters.

Key considerations

  • Authentication: Ensure proper setup and configuration of authentication (DKIM, etc.)
  • IP Type: Whether using shared or dedicated IPs can influence the warm-up strategy, with shared IPs potentially allowing for a slightly faster warm-up.
  • Sender Reputation: Domain reputation is important, but establishing a sender reputation on new IPs is essential to avoiding spam filters.

Expert view

Expert from Email Geeks answers that a warmup is needed when migrating to a new ESP, even with the same sending domain and address, due to new IPs, DKIM, and envelope domain. Suggests a quick warmup is possible with good practices given the volume.

3 Dec 2024 - Email Geeks

Expert view

Expert from Email Geeks responds that using shared IPs doesn't negate the need for a warmup, though it might allow for a slightly faster one. He emphasizes that the same authentication and IP considerations apply.

3 Nov 2021 - Email Geeks

What the documentation says

3 technical articles

Email delivery documentation from Google, SparkPost and AWS states that a warm-up period is necessary when migrating to a new ESP, even if you keep the same sending domain. This is primarily due to the new IP addresses associated with the ESP. A gradual increase in sending volume is essential to establish a positive sending reputation and avoid negative impacts from sudden volume spikes.

Key findings

  • IP Reputation is Key: New IPs require a reputation build-up even if the domain remains the same.
  • Gradual Volume Increase: A gradual increase in email sending volume is crucial for establishing a positive sending reputation.
  • Sudden Spikes are Harmful: Sudden spikes in email volume negatively impact sender reputation.

Key considerations

  • Volume Planning: Plan your sending volume increase to avoid sudden surges.
  • Monitor Reputation: Continuously monitor your sender reputation to identify and address any issues promptly.
  • New IP focus: Focus efforts on building a positive sending reputation from scratch on those new IPs.

Technical article

Documentation from Google Postmaster Tools explains that a sudden spike in email volume can negatively impact your sender reputation. It's important to gradually increase sending volume, especially when using new IPs or migrating to a new ESP, even with the same domain.

10 Aug 2023 - Google Postmaster Tools

Technical article

Documentation from SparkPost answers that even when maintaining the same sending domain, a warm-up is vital due to the new IP addresses associated with the new ESP. They emphasize the importance of building a positive sending reputation from scratch on those new IPs.

4 Apr 2023 - SparkPost

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