When warming up a new IP address, should you also warm up the 'from' address domain?
Michael Ko
Co-founder & CEO, Suped
Published 20 Jul 2025
Updated 18 Aug 2025
7 min read
When you are preparing to send emails from a new IP address, a common question arises: do I also need to warm up the 'from' address domain? The simple answer is yes, both the IP address and the domain associated with your 'from' address (the sending domain) require a strategic warm-up process.
Mailbox providers, like Microsoft and Yahoo, assess your sender reputation based on multiple factors. They look at your sending IP, the domain used in your 'from' address, and the domains used for email authentication, such as DKIM and SPF. A holistic approach ensures that your email stream is recognized as legitimate and trustworthy.
Ignoring one aspect can undermine the efforts you put into the other. For instance, a well-warmed IP sending from a cold domain might still face deliverability challenges. The goal of warming up is to gradually build a positive sending history and reputation with internet service providers (ISPs).
How email reputation is built
Email reputation is not a singular entity controlled by one factor, but rather a complex system influenced by various elements. ISPs evaluate multiple identifiers to determine if incoming mail is legitimate or potentially spam. Understanding these components is the first step toward successful email delivery.
IP reputation focuses on the sending server's trustworthiness. When you use a new dedicated IP, it has no prior sending history, meaning ISPs have no data on how you send email. Gradually increasing your sending volume from this IP allows ISPs to observe your sending patterns, response rates, and complaint rates, thereby building a reputation.
Domain reputation is tied to the 'from' domain (and any associated subdomains) used in your emails. This includes the domain visible in the 'from' field, as well as the domains used for authentication protocols such as SPF and DKIM. A strong domain reputation signals to ISPs that your brand is trustworthy, which is crucial for inbox placement. This is particularly important because more mailbox providers are shifting their focus towards domain reputation as a primary indicator of sender legitimacy.
IP reputation
Identified by: The numerical IP address from which emails originate.
Factors: Sending volume, consistency, spam complaints, bounce rates, and whether the IP has been listed on a blocklist.
Impact: Directly affects whether your emails are accepted by receiving servers or are sent to spam or rejected.
Domain reputation
Identified by: The 'from' domain in the email header and associated authentication domains.
Impact: Crucial for inbox placement, brand recognition, and avoiding the spam folder.
Why warm up both your IP and domain?
The answer to whether you should warm up both your IP and domain is an unequivocal yes. It's not an either/or scenario. Internet Service Providers (ISPs) don't just look at one identifier when assessing incoming mail, they consider a combination of factors.
If you're using a new IP address but an established domain, the IP still needs to build its own reputation. Conversely, a new domain on a warmed IP still needs to prove its trustworthiness to ISPs. Changing either the IP or the 'from' domain (or authenticated domains like your DKIM d= domain) can signal a new identity to ISPs, requiring a fresh introduction period.
Warming up both simultaneously ensures that your entire sending identity is gradually introduced and trusted by recipients. This dual approach helps mitigate risks, such as emails being sent to the spam folder, delayed, or even getting your sending IP or domain placed on a blocklist (or blacklist).
Integrated approach for reputation building
Consistent Identity: Always use the same 'from' address domain (and its authenticated subdomains) with the new IP address during the warm-up period. This helps ISPs consistently associate the sending IP with your brand identity.
Real Engagement: Send emails to your most engaged subscribers first. High open and click rates, coupled with low spam complaints, are crucial signals for both IP and domain reputation.
Gradual Escalation: Increase your sending volume gradually for both the IP and the domain. This methodical approach allows ISPs to build a positive profile for both elements over time.
Authentication: Ensure that your SPF, DKIM, and DMARC records are correctly configured for your sending domain and IP from day one.
Steps for a successful warm-up
A successful warm-up is about building trust gradually. It's akin to introducing yourself in a new neighborhood, you don't start by hosting a massive party. Instead, you get to know a few neighbors, then a few more, slowly building relationships.
The core principle for warming up a new IP address and its associated domain is a controlled, gradual increase in sending volume. Begin by sending small batches of emails to your most engaged subscribers who are likely to open, click, and not mark your emails as spam. This positive engagement helps establish a good reputation. Over time, you can incrementally increase the volume and broaden your audience.
Consistency is key throughout this period. Try to send emails regularly and stick to your warm-up schedule. Erratic sending patterns can raise suspicion with ISPs. It's also vital to monitor your deliverability rates and sender reputation metrics closely to identify and address any issues early.
Day
Volume increase
Maximum Emails (Cumulative)
Audience
1-3
1,000
1,000
Most active users, high engagement
4-7
2,000
3,000
Active users, slightly broader engagement
8-14
5,000
8,000
Regular users, expanding reach
15-21+
10,000+
Full volume
Entire mailing list (if engaged)
Ensure that your DNS records for SPF, DKIM, and DMARC are properly configured for your sending domain from the very beginning. These authentication protocols are critical for proving your legitimacy and ensuring mailbox providers can verify that your emails are truly from you. Incorrect or missing records can severely hinder your warm-up efforts.
It's also important to align your 'from' domain (the one recipients see) with your authenticated domains. This alignment is a key part of DMARC and tells ISPs that the sender is consistent and verified, further enhancing your reputation.
Avoiding common warm-up mistakes
Warming up a new IP address and domain requires patience and adherence to best practices. One of the biggest mistakes you can make is trying to rush the process. Sending too many emails too quickly from a new IP or domain is a red flag for ISPs and can lead to immediate deliverability issues.
Another common pitfall is sending to unengaged or low-quality lists during warm-up. This can result in high bounce rates, spam complaints, and low engagement, all of which negatively impact your sender reputation. It's crucial to send to active, opted-in subscribers who are expecting your emails.
Consequences of improper warming
Failing to warm up your IP and domain properly can have severe consequences for your email deliverability. Mailbox providers might throttle your sending, meaning your emails are delivered slowly, or block them entirely. Your emails could also be directed straight to the spam or junk folder, bypassing the inbox. In more severe cases, your IP address or domain could end up on a public or private blocklist (or blacklist), making it extremely difficult to reach your recipients.
Regularly monitor your email performance metrics, such as open rates, click-through rates, and complaint rates. Tools like Google Postmaster Tools can provide valuable insights into your domain's reputation with Gmail. Pay close attention to any warnings or sudden drops in deliverability. Being proactive allows you to adjust your sending strategy and prevent major issues.
Views from the trenches
Best practices
Gradually increase sending volume, starting with highly engaged segments of your audience.
Maintain consistent sending patterns throughout the warm-up period.
Ensure proper SPF, DKIM, and DMARC authentication for your domain and IP.
Monitor email deliverability metrics and ISP feedback loops closely to catch issues early.
Common pitfalls
Rushing the warm-up process by sending high volumes too soon can trigger spam filters.
Sending to unengaged or purchased lists will lead to high bounces and complaints, harming reputation.
Ignoring domain warming while only focusing on IP warming, or vice versa, creates an incomplete reputation.
Using fake email addresses or non-real recipients for warming, which does not build actual trust with ISPs.
Expert tips
Warming up is about proving to ISPs that your mail stream is good. Both the IP address and the authenticated domain (DKIM d= and SPF) are critical identifiers.
It's not an 'either/or' situation; ideally, you should warm up your authenticated domain and the IP address simultaneously.
Real email to real recipients is essential for effective warming. Any process using fake mail won't achieve the desired results.
When you change the domain (like the 'from' domain or the DKIM 'd=' domain), factor in a few extra days for ISPs' machine learning engines to adapt to the new identity.
Expert view
Expert from Email Geeks says that warming up is about introducing your mail stream as a source of good mail to the recipient ISP. ISPs identify a mail stream in a bunch of ways, but IP address, DKIM, and SPF are big ones, and you have direct control over these factors.
2023-09-01 - Email Geeks
Expert view
Expert from Email Geeks says that it's not a binary choice between warming up the IP or the domain; you ideally want to warm up your authenticated domain as well as the IP address for optimal results.
2023-09-02 - Email Geeks
Building trust for reliable delivery
The process of warming up a new IP address and its associated 'from' address domain is fundamental to achieving high email deliverability. By focusing on both aspects, you're building a comprehensive and trustworthy sender reputation with ISPs. It's a strategic investment that pays off in reliable inbox placement and strong engagement.
Remember, email deliverability is a marathon, not a sprint. Patience, consistency, and careful monitoring of your sending metrics are your best allies in ensuring your messages reach their intended recipients, free from spam folders or blocklist (or blacklist) issues.
