Cold email outreach is a powerful weapon for businesses, but it only works if you can ensure email deliverability—that is, the ability to hit the inbox rather than go to spam. Email warmup is one of the most critical steps in achieving high deliverability. It’s the practice of gradually increasing the volume of emails sent from your mail server so that email providers build a positive impression of you as a sender.
If your business is on a new domain, changing to a new email service provider, or running cold outreach campaigns, then you need to warm up to avoid being flagged as spam. Sending thousands of emails at once from the domains can raise a red flag from ESPs and such emails may get blocked.
Hence, traditional warmup methods were introduced—automated interactions where emails are sent and opened create a semblance of organic engagement. While this approach helps, it often falls short due to other factors like spam filters, low engagement rates, inconsistent inbox placements, and domain reputation issues. In a sense, you can say that traditional warmup methods are surface-level only.
In this article, we’ll explore Warmy’s email seed list as an alternative, how it compares to traditional warmup, and how to use a seed list as an email warmup alternative.
What is traditional email warmup?
Traditional email warmup is the process of gradually increasing the volume of emails sent from a new or inactive email account to establish a positive sender reputation with email service providers (ESPs) like Gmail, Outlook, and Yahoo. This will help you prove that you are the real deal and your emails will not end up in spam
For companies and individuals who use cold outreach, newsletters, or transactional emails, proper warmup makes sure their messages land in recipients’ inboxes, instead of being marked as spam. Instantaneously sending a high volume from a different or less active email (without warmup) can send red flags to ISPs—marking you and your messages untrustworthy.
How does traditional warmup work?
The traditional email warmup process typically follows a gradual, staged approach over several weeks:
- It starts with low-volume sending, like 5-10 per day to a list of recipients.
- The number of emails sent each day slowly increases while monitoring engagement.
- The focus is on avoiding spam triggers and increasing metrics like open rates.
- After 2-4 weeks, the transition into regular campaigns can occur while maintaining a strong sender reputation.
When it comes to the recipients involved in the warmup process, businesses go about it differently. Some prefer to implement the warmup process with a list of their most engaged recipients. That way, there’s a higher likelihood of them opening emails and engaging with the emails. Meanwhile, some take the time to create their own lists of recipients, and some buy pre-made lists from external parties.
Why traditional email warmup may not be enough
This is not to say traditional email warmup doesn’t work. It does—but depending on your goals, it may not be enough. Because while traditional email warmup is a crucial first step in improving deliverability, it doesn’t always guarantee inbox placement and long-term deliverability success. Additionally, traditional warmup doesn’t work with some email providers like Klaviyo, Omnisend, Mailchimp, and Shopify—which limits a lot of businesses that want to invest in warmup.
Many businesses still struggle with emails landing in spam, inconsistent results across different providers, and reputation issues that persist despite following warmup best practices.
One of the biggest limitations of automated warmup tools is they simulate engagement but they don’t really replicate real-world recipient behavior. Other limitations include:
Strict spam filters (even warmed up emails may land in spam)
- Email providers constantly update their spam filters to detect and block unwanted (or deemed suspicious) emails.
- Many email providers rely on advanced AI-based spam detection, which can identify automated interactions.
- Even if an email account has been warmed up, sudden spikes in sending volume or using the wrong content can still result in spam placement.
Low engagement or lack of genuine engagement
- ESPs evaluate engagement metrics, such as open rates, replies, and interactions to determine deliverability. Automated warmup services often rely on pre-set patterns rather than organic, real interactions.
- If engagement isn’t authentic, ESPs may ignore warmup interactions, making it harder to establish true credibility.
- Most automation actions only involve opening emails, and not really engaging with them.
Inconsistent inbox placement
- Not all email providers handle incoming emails the same way. What works for Gmail may not work for Outlook or Yahoo.
- Traditional warmup tools don’t always test across multiple ISPs, so it’s hard to understand inbox placement across different providers.
Stagnant IP & domain reputation
- Some warmup services rely on low-quality mailboxes for engagement, which may not influence major ISPs.
- If other factors like SPF, DKIM, DMARC, or previous domain history are not properly configured, warmup alone won’t fix reputation issues.
- Poor email content or aggressive sending behavior after warmup can still result in deliverability problems, even if the initial warmup was successful.
The need for a better solution: Warmy’s seed list warmup strategy
Automated warmup tools help improve sender reputation, but they often fail to provide real-world insights into how emails are treated by different email providers. Without visibility into data, businesses risk sending their campaigns blindly.
This is where Warmy’s seed lists come in. Our seed list warmup strategy goes beyond automated engagement and provides real-time inbox placement data, allowing senders to proactively identify and resolve deliverability issues before scaling their email campaigns.
What is a seed list and how does it work?
A seed list is a collection of test email addresses spread across different email service providers (ESPs) like Gmail, Outlook, Yahoo, and corporate email domains. These addresses are not real customers but are used to warm up the sender’s domain before engaging in a full on campaign.
Warmy’s seed list vs. traditional email warmup services: key differences
Traditional email warmup relies on automated opens, but Warmy’s seed lists take it up a notch by simulating actual human behavior. Plus, instead of blindly warming up an email domain using a simple list and hoping for the best, senders can see exactly where their emails land and why—giving them the ability to proactively optimize deliverability.
Why the seed list warmup strategy is a better alternative for deliverability optimization
Many email senders assume that traditional warmup alone is enough to establish a strong sender reputation, but as we’ve seen, automated warmup tools often fall short in other areas.
Warmy’s seed list warmup strategy definitely has the upper hand in the following items:
- It works across multiple ESPs, ensuring email performance is optimized for all major providers. Traditional warmup services don’t always account for ESP variations, meaning senders could unknowingly face deliverability issues with certain providers. Instead of a one-size-fits-all warmup, Warmy’s seed lists allow targeted adjustments per ISP, leading to higher inbox rates across all major email platforms.
- It helps diagnose spam placement issues. This allows senders to fix problems before they impact reputation. With seed lists, combined with Warmy’s template checker, you can help identify spam trigger words or formatting issues that might be hurting deliverability. Senders can test different subject lines, email structures, and sending domains to see which configurations achieve the best inbox placement.
Step-by-step guide: how to use a seed list for email warmup
Step 1: Select the right seed list provider
Choosing a reliable and diverse seed list provider is critical if you have long-term deliverability goals. A good and credible seed list provider must:
- have wide coverage across major ESPs
- have corporate and business email addresses
- provide real-time tracking and insights
Warmy.io’s advanced seed lists cover Gmail, Outlook, and recently added Yahoo. Additionally, Warmy’s seed lists contain genuine email addresses which mimic real receiver behavior. Users can choose the corresponding seed list for their preferred ESP. Aside from this, users can also customize the number of seeds and the number of senders. In summary, Warmy’s advanced seed lists have multiple layers of customization.
Step 2: Set up your seed list in your email sending platform
- Upload the seed list contacts into your email-sending platform as a separate segment.
- Create a test email campaign specifically for the seed list, separate from live customer emails.
Step 3: Send test emails to your seed list
- Use the same email templates as your real campaigns. This helps identify content-related spam triggers.
- Test across different ESPs (Gmail, Outlook, Yahoo, etc.) to ensure consistent inbox placement.
- Send at different times of the day as some filters are more sensitive at peak hours.
- Include variations in subject lines and content to determine what elements affect spam placement.
Hot tip: Use Warmy’s Free Test Email Template Checker to create emails that will not trigger spam filters
Step 4: Adjust your email setup for better deliverability
Depending on the data your seed list warmup strategy generates, you may have to spend some time adjusting your email setup accordingly.
For example, if emails land in spam, you will need to adjust email copy, avoid spam trigger words, reduce links, and test different subject lines. If there are authentication failures, you will need to correct DNS records and ensure proper alignment between sender domain and authentication policies.
Step 5: Gradually increase sending volume while monitoring performance
- Don’t go from sending 10 emails per day to 1,000 overnight just because your spam rates have gone down.
- Continue testing with a seed list even as you scale.
- Encourage responses and interactions to signal positive sender behavior.
- Stay consistent. Irregular sending patterns can raise red flags with ISPs.
Enhance your email warmup with Warmy.io’s advanced seed lists
If you’re looking for a powerful, data-driven approach to email warmup and deliverability optimization, Warmy.io is the ultimate solution. By combining automated email warmup, advanced seed list features, and advanced deliverability insights, Warmy helps businesses avoid spam filters, improve sender reputation, and ensure consistent inbox placement.
Unlike traditional warmup tools, Warmy.io doesn’t rely solely on automated interactions. While it leverages the power of technology for automated actions, it still puts a premium on the importance of human behavior.
Warmy offers the most advanced email seed list. It offers actual engagement—your emails are opened, scrolled through, clicked on, and replied to. If there are emails that land in spam, these are removed and marked as important to let the ESPs know you are credible.
More than just seed lists: Warmy.io’s complete deliverability toolkit
In addition to seed lists, Warmy.io provides a full suite of tools designed to help businesses achieve maximum email deliverability:
AI-powered email warmup
Warmy gradually increases the volume of emails sent to establish your domain’s credibility. However, it can actually send up to 5,000 warmup emails per day, which makes it a robust warmup tool. So in essence, Warmy uses automation to simulate human behavior to enhance email deliverability.
Comprehensive deliverability insights and reporting
The free email deliverability test from Warmy provides a comprehensive assessment of your emails and where they are landing. Here are some other examples of the valuable information and data the deliverability test provides:
- Inbox placement analysis: the percentage of your emails that end up in the spam folder, promotions tab, inbox, and even the unreceived ones.
- Blacklist status: Learn if your domain or IP is listed on any blacklists so you can proceed with the delisting process.
- Authentication verification: Assess your email reputation and verifies your email authentication settings such as SPF, DKIM, and DMARC.
Additionally, Warmy’s Domain Health Hub is on a level of its own. Instead of monitoring individual email addresses, Warmy.io provides a domain-level health dashboard so businesses can take a more strategic approach to email deliverability. The Domain Health Hub includes the following features:
- A domain health score based on a combination of various factors like authentication, blacklist status, and inbox placement tests. You’ll also be able to monitor your spam rate trends and overall deliverability performance with weekly or monthly tracking options.
- Comprehensive DNS status checks to easily validate SPF, DKIM, DMARC, rDNS, MX, and A records for stronger authentication & security.
- Optimized multi-domain monitoring so users can manage all their domains from one dashboard and identify which ones need immediate attention.
- Quick access to a detailed breakdown of health metrics, performance reports, and deliverability trends per domain.
Move beyond traditional warmup with Warmy
Traditional email warmup methods have their limitations, often leaving senders blind to inbox placement issues, spam triggers, and authentication gaps. Without real-time visibility, businesses risk damaging their sender reputation and losing valuable email engagement.
Discover how Warmy’s Seed List feature can revolutionize your email strategy today. Learn more here.
