Domain Warmup: How It Works (Fixed-Stage Model)

Modified on Fri, 18 Jul at 8:04 AM

What is Domain Warmup?

Domain warmup is the process of gradually increasing your daily email volume to build a trusted sender reputation with inbox providers like Gmail, Outlook, and Yahoo.

Without proper warmup, new domains are more likely to:

Be flagged as spam
Experience high bounce or complaint rates
Face email delivery blocks or delays

The software automates this process to help you build trust and maximize email deliverability.

What Warmup Model Is Used?

This system uses a fixed-stage, gradual warmup model, which means:

Each stage has a predefined daily sending limit
Progression only occurs when the full daily limit for the current stage is reached
If the daily limit is not met, the domain remains in the same stage
There are no hourly sending limits
You must send emails through the warming domain for progress to be tracked

Important: Sending beyond the daily limit is allowed, and emails will not be blocked.

Warmup Stage Breakdown

Stage	Daily Limit
1	1,000
2	2,500
3	5,000
4	6,500
5	8,000
6	10,000
7	14,000
8	20,000
9	25,000
10	35,000
11	50,000
12	80,000
13	125,000
14	175,000
15	250,000

Once the daily limit is reached, the system pauses additional sending from that domain until 12:00 AM UTC the next day. The next stage will automatically begin if the full daily limit was reached.

When Does Warmup Start?

For newly created domains: Warmup is automatically enabled when the domain is created and verified. No manual action is needed.

For existing domains: Warmup must be enabled manually. When you enable warmup on an existing domain, the system will automatically analyze:

Past email activity
Google Postmaster reputation data (if integrated)

Based on this, it will recommend the most suitable starting stage to ensure smooth warmup progression.

Who Can Use Email Warmup and How to Enable It

Email warmup is available for both the platform and your account using dedicated domains.

To enable warmup for an account domain:

Go to Account Settings
Click Email Services
Select SMTP Service
Go to the Dedicated Domain and IP tab
Choose your domain and click Start Warmup.

To enable warmup for your account domain:

Go to the Account Settings
Click Email Services
Select SMTP Service
Go to the Dedicated Domain and IP tab
Choose your domain and click Start Warmup.

Google Postmaster Integration (Recommended)

Integrating your domain with Google Postmaster Tools gives you access to key deliverability data, including:

Domain reputation (High, Medium, Low, Bad)
Spam complaint rates
Authentication status
Delivery and error metrics

If Google Postmaster is not yet connected or no data is available, the domain dashboard will notify you and guide you through setup.

Best Practices for a Successful Warmup

Send emails consistently every day
Use verified, opt-in contact lists
Avoid sudden spikes in volume
Avoid switching sender domains mid-campaign
Respect daily warmup limits to avoid future enforcement blocks

When Is Warmup Complete?

Your domain completes warmup when it reaches Stage 15 (250,000 emails/day). At that point, you will see a "Warmup Complete" label in the domain dashboard, and full-scale sending will be supported.