Warmup Duration

Learn the ideal warmup duration for IPs and domains. Gradually increase send volume over 30 days to build reputation and ensure high email deliverability.

How Many Days Should a Warmup Plan Run?

The duration of a warmup plan is critical for building a strong sender reputation. Selecting the right number of warmup days ensures a gradual and consistent increase in email sending volume, avoiding issues like spam flags or IP blacklisting.

Poor Warmup Strategy

  • Description: Sending a large volume of emails too quickly causes reputation to drop, as mailbox providers see it as suspicious. This can lead to spam filtering or IP blacklisting.

  • Lesson: Avoid sending high volumes immediately, as it harms sender reputation and deliverability.

Ideal Warmup Strategy

  • Description: Gradually increasing send volume over time helps reputation grow steadily. This approach builds trust with mailbox providers, ensuring better inbox placement.

  • Lesson: Slow, consistent growth in send volume is key to building a strong and reliable sender reputation.


Ideal Warmup Duration

  • Minimum Warmup Period: At least 15 days for low-volume campaigns or smaller email lists.

  • Recommended Warmup Period: 30 days is ideal for medium to high-volume campaigns, allowing sufficient time to build trust with mailbox providers.

  • Extended Warmup Period: 60 days or more for new domains or IPs that need extra time to establish a reliable sender reputation.


Factors Affecting Warmup Duration

  1. Email Volume:

    • For small campaigns, 15–20 days may be sufficient.

    • Large-scale campaigns require 30+ days for gradual scaling.

  2. Domain/IP Reputation:

    • New domains or recently registered IPs benefit from longer warmup plans.

    • Established domains/IPs with no history of spam require a shorter warmup period.

  3. Recipient Engagement:

    • High engagement rates (e.g., opens and clicks) may reduce the need for an extended warmup period.

    • Low engagement or high bounce rates may require extending the warmup period.

  4. Mailing Frequency:

    • Daily senders should aim for a 30-day warmup.

    • Weekly or occasional senders may extend to 60+ days for consistency.


  • Mailbox Provider Trust: Gradual volume increases signal authentic and trustworthy behavior.

  • Avoids Reputation Damage: Sudden spikes in volume can trigger spam filters or IP blacklisting.

  • Ensures Deliverability: Proper warmup ensures emails consistently land in the inbox, not spam folders.

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