Summary
The overwhelming consensus among experts, marketers, and email service documentation is that warming up a domain and/or IP address is crucial when migrating to a new ESP. This process involves gradually increasing sending volume to establish a positive sender reputation with ISPs, preventing emails from being flagged as spam. The main reason is that sender reputation does not transfer; moving to a new ESP essentially starts a clean slate. While some suggest that warming might be less critical for smaller lists when moving between shared IP ESPs, the advice generally leans toward a cautious, gradual approach to ensure deliverability. It's also important to monitor deliverability metrics and adjust sending strategies accordingly.
Key findings
- Reputation Reset: Migrating to a new ESP effectively resets sender reputation, requiring a warm-up period.
- Improved Deliverability: Warming up improves email deliverability and reduces the risk of emails landing in the spam folder.
- Gradual Approach: A gradual increase in sending volume is key to establishing trust with ISPs.
- Monitoring Is Essential: Continuously monitoring deliverability metrics allows for adjustments to the warm-up strategy.
Key considerations
- List Segmentation: Consider list size and engagement when determining the intensity of the warm-up process.
- ESP Type: Determine whether you are migrating between shared IP ESPs or to a dedicated IP, as this will affect the warming strategy.
- ESP Guidance: Consult the new ESP's recommendations, but independently verify their approach to warming.
- Consistent Sending: Maintain a consistent sending schedule to build a reliable reputation with ISPs.
What email marketers say
12 marketer opinions
The majority of email marketers and experts agree that warming up a domain or IP address when migrating to a new ESP is crucial for maintaining email deliverability. The primary reason is that sender reputation is tied to the IP address and/or domain, and a new ESP essentially means starting with a clean slate. Warming up involves gradually increasing sending volume to establish a positive reputation with ISPs and avoid being flagged as spam. While some suggest it might not be necessary for small lists when moving between shared IP ESPs, the consensus leans towards caution and a gradual approach. Some mention that you can choose to warm up an IP address manually, or have Amazon Pinpoint automatically manage the warm-up process for you.
Key opinions
- Sender Reputation: Sender reputation is key and tied to the IP address or domain; moving to a new ESP resets this reputation.
- Deliverability Impact: Warming up helps prevent emails from being marked as spam and improves deliverability rates.
- Gradual Increase: The warming process involves gradually increasing sending volume over time.
- Small Lists: For small lists when moving between shared IP ESPs, warming up might be less critical but is still generally recommended.
Key considerations
- List Size: Consider the size of your subscriber list; smaller lists might require less aggressive warming.
- ESP Type: Determine if you are moving between shared IP ESPs or to a dedicated IP, as this affects the urgency of warming.
- Monitoring: Actively monitor deliverability metrics during the warm-up process to adjust sending volume as needed.
- ESP Recommendations: Consult the new ESP's recommendations on warming, but exercise caution if they advise skipping the process altogether.
Marketer view
Email marketer from Email Geeks responds with "maybe", explaining that if moving from one shared IP ESP to another, the key question is the size and frequency of sending to the subscriber list. If the list is relatively small, warming may be unnecessary.
18 Oct 2022 - Email Geeks
Marketer view
Email marketer from GlockApps explains IP warming (also known as IP warm-up) is the practice of gradually increasing the volume of emails sent with a new IP address. This process allows you to build a positive sending reputation with ISPs and email providers. If you suddenly start sending a large volume of emails with a new IP, it can raise red flags and your emails may be marked as spam. Proper IP warming helps to ensure that your emails reach the inbox.
25 Jun 2022 - GlockApps
What the experts say
6 expert opinions
Experts generally agree that warming up a domain or IP address is crucial when migrating to a new ESP. Warming ensures filters recognize the new ESP as legitimate and helps build a good sender reputation. Without warming, there's a high risk of emails being marked as spam or blocked due to a lack of established reputation, regardless of the ESP configuration. Gradual increase of email volume is recommended.
Key opinions
- Sender Reputation: Warming is crucial for building sender reputation with the new ESP.
- Filter Recognition: Warming helps email filters recognize the new ESP as a legitimate source.
- Deliverability Risks: Failing to warm up can lead to spam folder placement or blocking.
- IP Importance: Each IP address builds its own reputation; good reputation is not inherited.
Key considerations
- Sending Strategy: Start with a low sending rate and gradually increase volume.
- Monitoring: Monitor deliverability metrics to adjust sending rates.
- ESP Advice: While deferring to ESPs is sometimes advised, confirm they have a sound warm-up plan or independently verify.
- Configuration: Consider migrating from shared to dedicated IPs also requires warming.
Expert view
Expert from Spam Resource shares that they are dealing with low deliverability and Google putting their emails in spam even though its opt-in subscribers. Spamresource recommends warming up your IP. Do this by sending small volumes of email and increasing your sending size as you go along.
23 Aug 2024 - Spam Resource
Expert view
Expert from Email Geeks answers that migrating from one platform to another, or even from shared to dedicated IPs, will require warming.
5 Aug 2021 - Email Geeks
What the documentation says
5 technical articles
Email service providers emphasize that warming up an IP address or domain is crucial when migrating to a new ESP. This process involves gradually increasing sending volume to establish a positive sender reputation with ISPs. When starting with a new IP or domain, ISPs treat the sender with suspicion until a reputation is built. Warming up is an opportunity to prove legitimacy and avoid being flagged as spam. All sources agree on the importance of a gradual increase in volume and continuous monitoring of sending reputation and deliverability metrics.
Key findings
- New IP = New Reputation: Switching to a new IP or domain means starting with a clean sender reputation.
- Gradual Volume Increase: Gradually increasing sending volume helps build trust with ISPs.
- Spam Prevention: Warming up prevents emails from being flagged as spam.
- Continuous Monitoring: Monitoring sender reputation and deliverability metrics is essential throughout the process.
Key considerations
- Consistent Sending: Aim for a consistent sending volume daily rather than large, infrequent sends.
- Postmaster Tools: Use available postmaster tools (e.g., Google Postmaster Tools) to monitor your sending reputation.
- Best Practices: Adhere to general email sending best practices during the warming period.
- Automated Warm-up: Consider using automated warm-up features offered by some ESPs.
Technical article
Documentation from Google explains to gradually increase the volume of mail sent using new IPs. Google recommends following the best practices for sending emails and monitor your sending reputation in Postmaster Tools.
15 Sep 2021 - Google
Technical article
Documentation from Postmark explains that warming an IP address or a sending domain is the process of building your sender reputation to improve your email deliverability. Every email sent from a new domain or IP address contributes to your reputation with mailbox providers. When starting out, your reputation is like a blank slate - mailbox providers don't know if you're a legitimate sender or a spammer. Warming up is an opportunity to show them that you are a responsible and trustworthy sender.
29 May 2021 - Postmark
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