Why do new domains need to be warmed up before sending cold emails?

A new domain lacks sender history and reputation. Without warmup, ESPs like Gmail will view sudden high volume as suspicious, leading to emails going to spam or the domain being blacklisted. Warmup builds trust by mimicking natural sending behavior.

How long does it take to warm up a new email domain?

The length varies, but typically, it takes 2-4 weeks. Factors include the volume of emails you plan to send, the quality of your initial recipient list, and how closely you adhere to best practices for domain warming . Consistency is more important than speed.

What happens if I don't warm up my new domain for cold emails?

The primary risk is severely damaging your sender reputation, which leads to your emails consistently landing in the spam folder or getting your domain placed on a blocklist (or blacklist). This can make it very difficult to achieve successful email deliverability in the future, even for legitimate sends.

What's the best approach to warming up a new domain for cold outreach?

Start with a very low volume (e.g., 5-10 emails per day) to engaged contacts or internal addresses. Gradually increase this volume by 10-20% daily or every few days. Monitor your domain reputation metrics and adjust your sending pace accordingly.

Is email warmup necessary for sending cold emails from a new domain? - Sender reputation - Email deliverability - Knowledge base

When you're embarking on a cold email campaign with a brand new domain, a common question arises: is email warmup truly necessary? The short answer is an emphatic yes. Imagine trying to run a marathon without any training, or opening a new business with no prior customer relationships. It's an uphill battle, and the same principle applies to email sending.

Email Service Providers (ESPs) and mailbox providers, such as Gmail and Outlook, are highly vigilant about new sending domains. A sudden surge of emails from an unfamiliar domain immediately raises red flags. This can lead to your emails being directed straight to the spam folder, or even worse, getting your domain flagged as suspicious and added to an email blacklist (or blocklist).

Why warmup is critical for new domains

Email deliverability hinges heavily on sender reputation. Think of it as a credit score for your email sending practices. When a domain is new, it has no history, no credit score. If you immediately begin sending large volumes of cold emails, ESPs have no basis to trust your domain. They'll likely classify it as potentially abusive traffic, designed to bypass spam filters.

The goal of warming up is to gradually build this reputation. By starting with small, manageable volumes and slowly increasing them, you demonstrate to ESPs that you are a legitimate sender. This process mimics natural email usage, where a new sender would typically begin with a few emails and slowly expand their outreach over time. This helps ESPs understand your sending patterns and build trust in your domain.

A good sender reputation ensures that your emails are more likely to reach the inbox, rather than being diverted to spam or junk folders. Without it, your cold email efforts, regardless of how well-crafted your content is, will likely fail to reach your intended audience.

The email warmup process

The email warmup process involves a strategic increase in email volume, combined with positive engagement signals. You start by sending a very small number of emails, perhaps 5-10 per day, to highly engaged recipients or even to accounts you control. As these emails are opened, replied to, and marked as 'not spam,' it sends positive signals back to the ESPs.

Over several weeks, you incrementally increase the volume. The key is consistency and gradual escalation. It’s also crucial to have proper email authentication protocols in place, such as SPF, DKIM, and DMARC. These records verify your domain's legitimacy and help prevent spoofing, further enhancing your sender reputation.

While this might sound tedious, skipping this step can be far more detrimental. A cold domain (one that hasn't sent email before, or has been inactive for a long time) that suddenly sends a high volume of emails is a classic spammer characteristic. ESPs are designed to detect and block such behavior to protect their users. This is where domain warming proves effective.

Key elements of a warmup strategy

Gradual volume increase: Start low and increase email sending volume incrementally over time.
Positive engagement: Aim for opens, clicks, and replies to signal good sending behavior.
Authentication protocols: Properly configure SPF, DKIM, and DMARC records.
Consistent sending: Maintain a steady sending rhythm, avoiding large, sporadic bursts.

Risks of skipping warmup for cold emails

Ignoring the warmup process, especially for cold emails, carries significant risks. When you send a high volume of emails from a new domain, ESPs have no prior data to assess your trustworthiness. This immediate high volume, without any established reputation, is a classic indicator of spamming behavior. Your emails will likely be flagged by spam filters.

The consequences can range from temporary blocks to permanent blacklisting of your domain. Once your domain is on a blocklist (or blacklist), it becomes incredibly difficult to send emails effectively. Future campaigns, even legitimate ones, will struggle to reach inboxes. Recovering a damaged sender reputation is a long and arduous process, often taking months.

Furthermore, a sudden influx of emails to potentially unengaged cold contacts can lead to high bounce rates and spam complaints. These negative signals further degrade your domain reputation, reinforcing the ESPs' suspicion that you're not a legitimate sender. It's a vicious cycle that can effectively cripple your email outreach efforts.

With warmup

Gradual trust-building: ESPs see natural sending patterns and build a positive reputation for your domain.
Higher inbox placement: Emails are more likely to reach the primary inbox.
Reduced spam complaints: Slower ramp-up allows for better list hygiene and targeting.
Long-term deliverability: Establishes a sustainable foundation for future campaigns.

Without warmup

Immediate red flags: ESPs instantly identify sudden high volume from a new domain as suspicious.
Spam folder destination: Your cold emails will likely land in spam or junk.
Domain blacklisting: Risk of being added to email blocklists, severely hindering future sending.
Wasted efforts: Campaigns yield poor results due to low deliverability and engagement.

Effective warmup strategies

To effectively warm up a new domain for cold emails, consistency and patience are paramount. Start by sending to a small, highly responsive segment of your audience, or even internal email addresses you control. This helps generate early positive engagement signals.

Gradually increase your sending volume over several weeks. A common approach is to increase volume by 10-20% daily, but this can vary based on your domain's age and the ESPs you're targeting. Pay close attention to your deliverability rates and sender reputation metrics using tools like Google Postmaster Tools. If you notice a dip in deliverability or an increase in complaints, slow down your sending.

Maintaining a clean email list is also crucial during and after warmup. Regularly remove inactive or invalid email addresses to minimize bounces and complaints. This signals to ESPs that you are a responsible sender and helps preserve your hard-earned sender reputation.

Warmup phase	Daily volume target	Key activities
Week 1	5-20	Send to highly engaged, known contacts. Focus on getting opens and replies.
Week 2	20-50	Slowly introduce small segments of your cold list. Monitor bounce and spam rates.
Week 3	50-100	Continue increasing volume. Maintain consistent sending patterns and monitor feedback.
Week 4+	100+	Gradually scale up based on performance. Always prioritize deliverability and sender reputation.

Views from the trenches

Best practices

Prioritize genuine engagement to build trust with internet service providers.

Segment your cold email list to send to the most relevant recipients first.

Regularly monitor your domain's reputation and deliverability metrics.

Common pitfalls

Sending a sudden high volume of emails from a new domain, leading to immediate blacklisting.

Ignoring bounce rates and spam complaints, which severely damage sender reputation.

Not maintaining a clean email list, resulting in low engagement and increased spam trap hits.

Expert tips

Implement a dedicated domain warming tool to automate and optimize the process.

Gradually introduce different email content types and formats during the warmup period.

Focus on establishing consistent sending patterns rather than sporadic bursts of emails.

Expert view

Expert from Email Geeks says cold email is spam and goes against permission-based communities.

2024-05-07 - Email Geeks

Expert view

Expert from Email Geeks says they successfully suspended a cold email spammer's domain registration.

2024-05-07 - Email Geeks

The path to deliverability success

In summary, email warmup is not just recommended, it's a critical prerequisite for anyone planning to send cold emails from a new domain. It’s the foundational step for building trust with ESPs and ensuring your messages actually reach your target audience's inboxes. Skipping this phase is a direct path to low deliverability, poor sender reputation, and potential blacklisting.

Investing the time and effort into a proper email warmup strategy will save you from future headaches and significantly increase the success rate of your cold email campaigns. It sets the stage for a healthy and sustainable email sending future.