How to Send Your Campaign in Batches to Warm Up Your Domain

Last updated August 27, 2025

Email domain warmup signals your service provider that you are not a robot or scammer. Preparing a high-volume campaign from a new account is crucial.

With Mailmodo’s Fragmented Scheduling feature, you can schedule bulk email campaigns in increments over seven days. Fragmented Scheduling is particularly useful for warmup campaigns, where gradually increasing your sending volume helps establish trust with mailbox providers and ensures better deliverability.

In 2019, Google took more stringent steps from email sending and receiving sides to detect spam emails. The email service provider gives daily sending limits when a user opens a new email account. However, a new account can’t use it entirely. Ideally, it takes 8-12 weeks to accomplish maximum deliverability.

Here’s our definitive guide to Domain Warmup to help you get started with understanding the warmup process.

Fragmented Scheduling requires you to configure the schedule only once, after which an automated flow manages the distribution as per your configuration. This method supports email deliverability best practices while helping you scale efficiently.

Why Use Fragmented Scheduling?

Improves Deliverability: Gradual sending helps establish sender reputation with mailbox providers, avoiding sudden spikes that might flag your domain
Automates Warm-Up: After configuring, the system automatically adjusts sending volumes and schedules
Flexible Scheduling: You can select specific days, time frames, and increments to control email distribution effectively
Supports Engagement Tracking: Allows you to observe how recipients interact with emails over smaller batches, making adjustments as necessary

Setting Up a Fragmented Campaign (Step-by-Step)

Step 1: Create Your Campaign

Navigate to Campaigns in Mailmodo
Create a bulk campaign as usual
In this select template -> add details -> select contacts -> review and send

How to Send Your Campaign in Batches to Warm Up Your Domain

In review and send instead of selecting now select schedule options

Step 2: Enable Fragmented Scheduling

Choose the option: ‘Send in batches at regular intervals (up to 7 days)’

Configure the first batch. You can choose to send it Now or Later

Step 3: Select Days and Time Duration

Define the specific days of the week and time windows during which your campaign should be sent
If you select the Later option, choose the start date and time for the campaign

Fill in the initial volume of users to be sent emails in the first batch
Specify the time interval between consecutive batches (e.g., every 12 hours, daily)

Note: The ending time should always be after the starting time within a 24-hour window

Step 4: Set Initial Batch Volume and Intervals

Step 5: Configure Volume Increments

Use the increment factor to grow your batch sizes over time. For example if you set If you set the increment factor to 1.5x & at every 24 hours, the volumes will increase as follows in batches:

Batch	Volume
Day 1	200
Day 2	300
Day 3	450
Day 4	675
Day 5	1012
Day 6	1518
Day 7	2277

Step 6: Pause Between Campaigns (Optional)

Add pauses during specific timeframe (e.g., overnight or weekends) to ensure no emails are sent during the designated period
After configuring the schedule, click on ‘Preview Campaign’
Review the overview of your schedule, including batch sizes, send intervals, and total duration
If satisfied, enable the campaign

Step 7: Preview and Enable Campaign

Note: You can always return to edit the campaign schedule if needed

Best Practices for Warm-Up Campaigns

Start Small: Begin with low volumes (e.g., 200-500 recipients per day) and scale up gradually
Focus on Engaged Segments: Send to your most active and engaged subscribers initially to build domain reputation faster
Avoid Risky Lists: Do not include unengaged or inactive users during the warm-up phase, as this can harm deliverability
Monitor Metrics: Track key performance indicators (added below) and make adjustments to your sending schedule based on these metrics.

Open rates
Click rates
Bounce rates
Spam complaints

Creative Rotation: It’s best practice to refresh your email creatives every 3 days during the warm-up schedule to maintain engagement and signal healthy sender behavior.
Stay Consistent: Maintain a regular sending cadence after warming up to avoid losing reputation with mailbox providers

By following these steps and best practices, Mailmodo’s Fragmented Scheduling feature can help you seamlessly warm up your domain, improve your email deliverability, and prepare for higher volume campaigns.

For further assistance, check out our comprehensive guide on email deliverability or contact our support team .

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How to Send Your Campaign in Batches to Warm Up Your Domain

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Why Use Fragmented Scheduling?