Summary
Experts, email marketers, and documentation from various sources consistently emphasize the importance of warming up both the IP address and the 'from' address domain for optimal email deliverability. A positive sender reputation relies on this dual warmup, as it helps ISPs recognize and trust the mail stream. This involves aligning domain authentication (SPF, DKIM, DMARC) with the sending IP address, maintaining a good domain reputation through engaging content, and ensuring proper DNS setup. Neglecting domain warmup, using inconsistent subdomains, or changing the domain can lead to deliverability issues, requiring additional time for ISPs' machine learning systems to adjust.
Key findings
- Dual Warmup: Warming up both the IP address and the 'from' address domain is crucial for a positive sender reputation and email deliverability.
- Domain Reputation: Domain reputation is as important as IP reputation and directly impacts the IP warmup process.
- Authentication Alignment: Aligning domain authentication (SPF, DKIM, DMARC) with the sending IP address is essential for associating the IP with a legitimate domain.
- DNS Setup: Properly configured DNS records aid in associating a good sending reputation with the new IP.
Key considerations
- Neglecting Domain Warmup: Neglecting domain warmup during IP warmup can lead to deliverability issues.
- Inconsistent Subdomains: Avoid using different subdomains than the domain originally warmed up to prevent flagging by ISPs.
- Content Engagement: Focus on sending engaging content to build and maintain a positive domain reputation.
- Domain Changes: Changing the domain requires additional time for ISPs' machine learning systems to adjust.
- Monitor Reputation: Monitor reputation using tools like Google Postmaster Tools to track progress and identify problems.
What email marketers say
6 marketer opinions
Warming up both the IP address and the 'from' address domain is crucial for establishing a positive sender reputation and ensuring email deliverability. Neglecting domain warmup or using inconsistent subdomains can lead to deliverability issues. Proper domain authentication (SPF, DKIM, DMARC) and DNS setup, alongside engaging content, are essential for building trust with mailbox providers.
Key opinions
- Dual Warmup: Both IP and domain warmup are necessary for a positive sender reputation.
- Domain Reputation: Domain reputation is as important as IP reputation.
- Authentication Alignment: Proper domain authentication (SPF, DKIM, DMARC) must align with the sending IP.
- DNS Setup: Correctly configured DNS records aid in associating a good sending reputation with the new IP.
Key considerations
- Inconsistent Subdomains: Avoid sending from different subdomains after IP warmup to prevent flagging by ISPs.
- Engaging Content: Send engaging content to build and maintain a positive domain reputation.
- Email Best Practices: Adhere to email best practices to improve deliverability and sender reputation.
- Neglecting domain warmup: Neglecting domain warmup during IP warmup can lead to deliverability issues.
Marketer view
Email marketer from GlockApps explains that domain reputation is as important as IP reputation. When warming up an IP address, you should also focus on building and maintaining a positive domain reputation by sending engaging content and adhering to email best practices.
15 Jun 2025 - GlockApps
Marketer view
Email marketer from MailerQ recommends that DNS records should be properly set up for the domain from which emails are being sent. This aids the email provider in associating a good sending reputation with the new IP in question
4 Oct 2022 - MailerQ
What the experts say
4 expert opinions
Experts agree that warming up both the IP address and the 'from' address domain is essential for establishing a trusted mail stream with ISPs. This involves aligning domain authentication (SPF, DKIM) with the IP address and ensuring the domain has a positive reputation. Changing the domain during or after IP warmup requires additional time for ISPs' machine learning systems to adjust.
Key opinions
- Dual Warmup Importance: Warming up both the IP address and the authenticated domain is crucial for optimal deliverability.
- Authentication Alignment: Aligning domain authentication (SPF, DKIM) with the IP address is vital for associating the IP with a legitimate domain.
- Domain Reputation Impact: A domain's reputation directly affects the IP warmup process; a poor or non-existent domain reputation can hinder IP warmup.
- Machine Learning Adjustment: Changing the domain after or during the warmup requires additional time for ISPs machine learning to adjust.
Key considerations
- Gradual Introduction: Introduce your mail stream as a source of good mail to the recipient ISP gradually.
- Time for Domain Changes: Budget additional time for ISPs to recognize domain changes, as it impacts identity mapping.
- Monitoring Reputation: Continuously monitor and manage both IP and domain reputation to maintain deliverability.
Expert view
Expert from Email Geeks shares that changing the domain requires additional time for 'introduction' because identity is mapped to various domain aspects and IP addresses. Changes may require a few days for the ML engine to adjust.
25 Feb 2025 - Email Geeks
Expert view
Expert from Email Geeks explains warming up involves introducing your mail stream as a source of good mail to the recipient ISP, identifying it by IP address, DKIM, and SPF. Ideally, both the IP address and the authenticated domain should be warmed up.
21 Sep 2023 - Email Geeks
What the documentation says
4 technical articles
Leading email service providers (SparkPost, SendGrid) and email platforms (Google, Microsoft) emphasize that warming up both the IP address and the sending domain is crucial for achieving optimal email deliverability. Domain reputation significantly impacts deliverability, and warming it up involves gradually increasing sending volume and monitoring reputation metrics.
Key findings
- Dual Warmup Requirement: Warming up both the IP address and the sending domain is necessary for optimal deliverability.
- Domain Reputation Impact: Domain reputation plays a significant role in email deliverability.
- Gradual Increase: Warming up a domain involves gradually increasing sending volume.
- Platform Monitoring: Email platforms such as Google and Microsoft monitor Domain reputations.
Key considerations
- Inconsistent Results: Warming up only one aspect (IP or domain) can lead to inconsistent results and hinder deliverability.
- Reputation Metrics: Monitor reputation metrics using tools like Google Postmaster Tools to track progress and identify issues.
- Trust Establishment: Warming up both IP and Domain ensures that ISPs recognize and trust your mail stream.
Technical article
Documentation from Microsoft explains that they keep track of domain reputations. During an IP warm up, this reputation also needs to be established in conjunction with the new IPs so deliverability is maintained to their customer base.
24 Jul 2022 - Microsoft
Technical article
Documentation from SendGrid states that to achieve optimal deliverability, you should warm up both your IP address and sending domain. Warming up only one aspect can lead to inconsistent results and hinder overall deliverability.
2 Jun 2025 - SendGrid
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