Summary
IP warming is the gradual process of increasing email volume from a new IP address to establish a positive sending reputation. Experts and documentation recommend starting with a small segment of highly engaged users, sending quality content, and then incrementally increasing volume while closely monitoring deliverability metrics like bounce rates and spam complaints. Authentication (SPF, DKIM, DMARC) is crucial, as is adapting the strategy based on specific sending scenarios and feedback from mailbox providers. It's also important to view the process as a form of communication with mailbox providers.
Key findings
- Engage First: Start with a small group of your most engaged subscribers to establish a baseline of positive interactions.
- Gradual Growth: Increase sending volume gradually to avoid triggering spam filters and allow mailbox providers to assess your reputation.
- Monitor Metrics: Continuously monitor bounce rates, spam complaints, and engagement metrics to identify and address potential deliverability issues.
- Authenticate Email: Implement SPF, DKIM, and DMARC to verify your sending identity and improve deliverability.
- Communicate with Providers: View the warming process as a form of communication with mailbox providers, demonstrating that you send wanted mail to real users.
Key considerations
- Conservative vs. Aggressive: Determine an appropriate growth rate, considering factors like your specific sending situation and risk tolerance.
- Scenario Specifics: Adjust your approach based on whether you're warming a cold IP or migrating an existing domain.
- ESP Data: Consider consulting with your ESP to leverage their data on effective warming strategies for their platform.
- Respond to Issues: Be prepared to reduce sending volume if you encounter deliverability problems during the warm-up process ('back off').
- Define Goals: Establish clear goals for your mailings and how to measure against them
What email marketers say
9 marketer opinions
The consensus on warming up an IP address for email sending involves starting with a small, highly engaged segment of your audience and gradually increasing volume. Monitoring key metrics like bounce rates, spam complaints, and engagement (opens, clicks) is crucial to adjusting your schedule. Sending quality content, focusing on list hygiene, and potentially starting with transactional emails are also recommended to build a positive sending reputation.
Key opinions
- Start Small: Begin with a small segment of your most engaged subscribers to ensure positive initial interactions.
- Gradual Increase: Incrementally increase sending volume over time to avoid triggering spam filters.
- Monitor Metrics: Closely track bounce rates, spam complaints, and engagement metrics (opens, clicks) to identify and address deliverability issues.
- Quality Content: Send relevant, valuable content that recipients want to receive to improve engagement.
- List Hygiene: Maintain a clean email list by removing inactive or unengaged subscribers to improve your sender reputation.
Key considerations
- Engagement Levels: Segment your audience based on engagement levels to target your most responsive subscribers during the initial warm-up phase.
- Schedule Adjustment: Be prepared to adjust your sending schedule based on the performance of your campaigns and any deliverability issues that arise.
- Transactional First: Consider starting with transactional emails to establish a base reputation before sending marketing emails.
- Reputation Monitoring: Continuously monitor your sender reputation with mailbox providers to identify and address any issues promptly.
- Double Volume (with caution): One strategy suggests doubling volume daily, but it's critical to monitor carefully and slow down if bounces exceed 5%.
Marketer view
Email marketer from Litmus emphasizes the importance of a methodical IP warm-up, they suggest starting with a small segment of your most engaged subscribers and gradually increasing volume. Closely monitor deliverability metrics and adjust the schedule as needed to avoid issues like bounces and spam complaints.
29 Dec 2023 - Litmus
Marketer view
Email marketer from HubSpot recommends segmenting your contacts by engagement level and gradually increase the volume of emails you send to each segment, and closely monitor your sender reputation.
5 Jun 2024 - HubSpot
What the experts say
13 expert opinions
Experts emphasize the importance of a gradual IP warming process. This involves starting with a low sending volume to highly engaged users and carefully increasing it over time, with a focus on positive recipient engagement. Strategies should be tailored to specific sending scenarios (e.g., cold IP vs. domain migration). Close monitoring of deliverability metrics like bounce and complaint rates is essential. Authentication (SPF, DKIM, DMARC) setup is critical and consulting ESP data is recommended. Some advocate a conservative approach, and it's crucial to view warming as communicating with mailbox providers to demonstrate sender trustworthiness.
Key opinions
- Start with Engagement: Focus on sending to recipients who actively want your email and are likely to engage positively.
- Gradual Increase: Incrementally raise sending volume over a defined period, allowing mailbox providers to assess your reputation.
- Monitor Deliverability: Closely track metrics like bounce rates and complaint rates to identify and address potential issues promptly.
- Authentication: Implement email authentication protocols (SPF, DKIM, DMARC) to verify your identity and improve deliverability.
- Warming = Communication: Think of warming as establishing communication with mailbox providers about the content.
Key considerations
- Conservative vs. Aggressive: Determine an appropriate growth rate (e.g., 30-50% daily, doubling weekly) based on your specific sending situation and risk tolerance, with some experts advocating a more conservative approach.
- Specific Scenarios: Adjust your warm-up strategy depending on whether you are warming a completely cold IP address or migrating an existing domain.
- Data from ESPs: Consider consulting with your ESP to leverage their data on effective warm-up strategies for their platform.
- Back Off If Needed: Be prepared to reduce sending volume ('back off') if you encounter deliverability issues during the warm-up process.
- Defined Goals: Before starting to warm-up your IP, define the goals of your mailing and how you will measure against them.
Expert view
Expert from Email Geeks recommends Jennifer Lantz's guide to IP warming: <https://www.spamresource.com/2022/01/the-definitive-guide-to-ip-warming.html>.
5 Jul 2024 - Email Geeks
Expert view
Expert from Email Geeks shares a SendGrid help document they've used before for IP warming schedules: <https://sendgrid.com/en-us/resource/email-guide-ip-warm-up#chapter-5-sample-transactional-email-schedule>
22 Jun 2022 - Email Geeks
What the documentation says
5 technical articles
Email sending documentation consistently describes IP warming as a process of gradually increasing email volume from a new IP to build a positive sending reputation with ISPs. The core strategy involves starting with low volumes targeted at highly engaged users, then incrementally scaling sends while closely monitoring deliverability metrics (bounces, complaints, blocklist status) and adjusting sending schedules accordingly. Authentication and adherence to sender guidelines are also crucial.
Key findings
- Gradual Volume Increase: A gradual increase in email volume is the foundation of IP warming.
- Engaged Subscribers First: Start by sending to your most engaged subscribers.
- Monitor Deliverability: Closely monitor bounce rates, spam complaints, and blocklist status.
- Build Sending Reputation: The goal is to build a positive sending reputation.
Key considerations
- Authentication: Ensure proper email authentication (SPF, DKIM, DMARC).
- Throttling: Review and adhere to best practices for throttling email sending rates.
- Sender Guidelines: Adhere to the specific sender guidelines of each ISP (e.g., Google).
- Consistent Volume: Strive for a consistent sending volume.
Technical article
Documentation from Google Postmaster Tools mentions gradually increasing sending volume is important. They emphasize the need to authenticate your emails and adhere to their sender guidelines to establish a positive reputation. Monitor your reputation using their tools and adapt based on the data.
18 Jun 2022 - Google
Technical article
Documentation from SparkPost outlines that IP warm-up is a strategy to establish a good sending reputation. The best practice involves beginning with small, targeted sends to engaged users and increasing volume gradually as your reputation improves. They advise close monitoring of bounce rates, spam complaints, and blocklist status.
8 Jun 2023 - SparkPost
Are domain warmup tools like Lemwarm or WarmupInbox effective and safe to use?
Are IP warming services effective for improving email deliverability?
Do I need an IP warm-up when moving to a new ESP with shared IPs?
How do I warm up a new IP address for transactional emails?
How do I warm up new IP addresses for email sending?
How long does it take to warm up an IP address for email marketing?
