Summary
Warming up new IPs for transactional emails requires a gradual approach focused on building a positive sender reputation. Experts and marketers agree on starting with low volumes to engaged users, segmenting lists, and increasing volume incrementally. Monitoring deliverability metrics such as bounce rates, spam complaints, and engagement is crucial. Consistent sending habits, proper authentication (SPF, DKIM, DMARC), and adherence to best practices are essential. Avoid warming up too many IPs at once and keep spam rates low to ensure optimal deliverability.
Key findings
- Gradual Increase: Gradually increase email volume and frequency to establish a positive sender reputation with ISPs.
- Engaged Users: Start by sending emails to engaged users who actively want to receive your messages to minimize spam complaints.
- Monitor Metrics: Closely monitor deliverability metrics like bounce rates, spam complaints, and engagement during the warmup process.
- Segmentation: Segment your email list and gradually introduce the new IP to smaller, highly engaged segments first.
- Authentication: Ensure emails are properly authenticated using SPF, DKIM, and DMARC to build trust with ISPs.
- Consistent Sending: Establish consistent sending habits by scheduling emails and sticking to that schedule.
- Reputation Monitoring: Closely monitor your sending reputation by checking blocklists, bounce rates, and complaint rates.
Key considerations
- IP Volume: Avoid warming up too many IPs simultaneously, as it can be perceived as a sign of spamming.
- Warmup Pace: Adopt a slow and steady approach, as starting too fast can damage your reputation and lead to deliverability issues.
- Spam Threshold: Keep spam rates low, aiming below 0.2% to 0.3%, to maintain a positive sender reputation.
- Feedback Loops: Actively monitor feedback loops and address any complaints promptly.
- New Sender Focus: New senders should especially prioritize IP warming to establish a good reputation from the start.
- Right Mail to Right Users: Warm up IPs gradually by sending the right mail to the right users to build trust.
What email marketers say
12 marketer opinions
Warming up new IPs for transactional emails involves establishing a positive sender reputation by gradually increasing email volume to engaged users. Starting slow, monitoring deliverability metrics, and maintaining consistent sending habits are crucial. Avoid sending from too many IPs at once, and keep spam rates low.
Key opinions
- Gradual Increase: Gradually increase email volume and frequency to build a sender reputation with ISPs.
- Engaged Users: Focus on sending to engaged users who want to receive your messages to minimize spam complaints.
- Monitor Metrics: Closely monitor deliverability metrics like bounce rates, spam complaints, and engagement during the warmup.
- Segment Lists: Segment your email list and introduce the new IP to smaller, highly engaged segments first.
- Consistency: Establish consistent sending habits by scheduling emails to help ISPs recognize your sending patterns as legitimate.
- Transactional Focus: Focus on sending transactional emails, which are generally anticipated and less likely to be marked as spam, during the initial period.
- Spam Threshold: Keep spam rates low, aiming below 0.2%, as even a small percentage can negatively impact deliverability.
Key considerations
- IP Volume: Avoid warming up too many IPs simultaneously, as it can be perceived as spamming behavior.
- Warmup Schedule: Implement a gradual warmup schedule (e.g., doubling email volume every day or every other day over two weeks) to build trust.
- New Senders: New senders should prioritize IP warming to establish a positive sender reputation from the start.
- Slow & Steady: A slow and steady approach to IP warming is best to prevent damage to your reputation and avoid deliverability problems.
Marketer view
Email marketer from Email on Acid recommends monitoring bounce rates and complaint rates closely during the warm-up process. High bounce or complaint rates indicate deliverability issues that need to be addressed immediately.
4 Feb 2025 - Email on Acid
Marketer view
Marketer from Email Geeks suggests that using multiple IPs for the same sender can appear as obvious spam. Even if the mailings are legitimate, many sending IPs for the same content can raise suspicion.
8 Apr 2024 - Email Geeks
What the experts say
4 expert opinions
Warming up new IPs effectively involves gradual and targeted email sending, focusing on reputation monitoring. Sending too many emails too quickly or using an excessive number of IPs can harm your sender reputation. Complaints should be assessed within the context of Feedback Loops (FBLs), and overall sender reputation should be closely monitored via blocklists, bounce rates, and engagement metrics.
Key opinions
- Gradual Warmup: Gradual IP warm-up by sending the right mail to the right users.
- Reputation Monitoring: Closely monitor your sending reputation by tracking blocklists, bounce rates, complaints, and engagement.
- IP Volume: Warming up too many IPs at once is not advisable and can make you look like a snowshoer.
- Complaint Context: A 4% spam rate (one complaint in 20 messages) might be acceptable for initial sendings, but only if ISPs provide Feedback Loops (FBLs).
Key considerations
- Targeted Sending: Focus on sending the right mail to the right users during the warm-up process to build a positive reputation.
- Monitor Sending: Be mindful of sending too many emails too quickly, potentially damaging sender reputation.
- IP Usage: Avoid using an excessive number of IPs, as it can raise suspicion with ISPs.
- FBLs Importance: When assessing complaints, consider whether you are receiving feedback through Feedback Loops (FBLs) for accurate measurement.
Expert view
Expert from Spam Resource recommends closely monitoring your sending reputation during the IP warming process. This involves checking blocklists, bounce rates, complaint rates, and engagement metrics to ensure your IP is building a positive reputation with ISPs.
13 Aug 2024 - Spam Resource
Expert view
Expert from Email Geeks explains that warming up 60 IPs at once is not advisable. If you don't have many customers, using too many IPs can make you look like a snowshoer. You can send 1,000,000+ emails per day per IP, so warming up only 2 IPs might be sufficient. Give new large customers their own dedicated IP and let them warm it up.
9 Jul 2024 - Email Geeks
What the documentation says
4 technical articles
Effective IP warming involves a gradual and strategic approach to build a positive sender reputation. All documentation highlights the importance of sending to engaged users and increasing volume incrementally. Domain authentication using SPF, DKIM, and DMARC is crucial. Monitoring feedback loops and overall sender reputation, including bounce and complaint rates, are essential for maintaining good deliverability.
Key findings
- Small Volumes: Start by sending small volumes of emails.
- Engaged Users: Send emails to recipients who actively want to receive them (engaged subscribers).
- Gradual Increase: Slowly increase email volume over time based on positive engagement.
- Authentication: Ensure emails are authenticated using SPF, DKIM, and DMARC.
- Sender Reputation: Maintaining a good sender reputation is critical for deliverability.
Key considerations
- Monitoring: Monitor sending limits and metrics like bounce rates and spam complaints.
- Feedback Loops: Monitor feedback loops to address issues and avoid being flagged as spam.
- Best Practices: Adhere to email sending best practices.
Technical article
Documentation from SparkPost details that IP warming allows you to build a sending reputation with ISPs. They advise starting with your best traffic—emails to engaged subscribers—and gradually increasing volume based on positive engagement. They also recommend tracking metrics like bounces and spam complaints.
12 Sep 2023 - SparkPost
Technical article
Documentation from Amazon Web Services emphasizes sending small volumes of emails to recipients who actively want to receive your messages. They suggest monitoring your sending limits and slowly increasing the volume of emails you send over time.
15 Sep 2021 - Amazon Web Services
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