Email warmup is the process of gradually building your email account’s sending reputation with email service providers (ESPs) like Gmail, Outlook, and others. This process involves sending a steadily increasing volume of emails that generate positive engagement signals.

Why Warmup Is Critical for Cold Email Success

New or inactive email accounts that suddenly start sending large volumes of emails to unfamiliar recipients raise red flags with ESPs. This often results in:

Emails being sent directly to spam folders
Account sending limits being restricted
In severe cases, account suspensions

Warming up your inbox properly signals to ESPs that you’re a legitimate sender who follows best practices, significantly improving your deliverability rates.

How Reachkit’s Warmup Network Works

Reachkit’s automated warmup system:

Sends emails from your connected inboxes to other accounts in our warmup network
Automatically replies to these emails, creating positive engagement signals
Rescues emails from spam when necessary, training ESPs to recognize your emails as valuable
Gradually increases sending volume according to your configured settings
Monitors performance to ensure healthy reputation building

Key Warmup Benefits

Higher Inbox Placement: Properly warmed accounts see dramatically better inbox placement rates
Improved Sender Reputation: Build a positive sending history that carries forward
Reduced Risk: Minimize the chances of account restrictions or blacklisting
Ongoing Protection: Continuous warmup maintains reputation even during campaign pauses

How Long Should You Warm Up?

For new or inactive email accounts:

Minimum: 3 weeks of warmup before starting campaigns
Recommended: 4-6 weeks for optimal results

For established accounts:

Ongoing warmup is recommended to maintain reputation

Next Steps

Ready to start warming up your inboxes? Check out our guide on How to Enable and Configure Warmup in Reachkit to get started.