---
title: "How to set the send interval and sending window"
description: "Set the send interval, active days, timezone and sending window for a Smartlead campaign, and see how many sends fit each day."
url: https://helpcenter.smartlead.ai/en/articles/485-how-to-set-the-send-interval-and-sending-window
collection: "Creating Email Campaigns"
updated: 2026-11-10
language: en
---

# How to set the send interval and sending window

Set the send interval, active days, timezone and sending window for a Smartlead campaign, and see how many sends fit each day.

Your campaign schedule sets when emails go out. On the campaign's **Settings** tab, you choose the active days, the sending window, the timezone and the gap between emails. Use this guide to make sends follow your working hours or to spread a campaign across the day.

## Step 1: Open the schedule settings

1.  Open the campaign you want to change.
    
2.  Click the **Settings** tab.
    
3.  In the settings sidebar, click **Schedule Configuration**.
    

## Step 2: Set the timezone, active days and sending window

1.  In **Send Schedule**, choose a **Timezone**. Send times follow the campaign's timezone.
    
2.  Under **Active Days**, click each day you want to send on. Click a day again to turn it off.
    
3.  Under **Sending Window**, enter a time in **From** and a time in **To**. Type a time such as `09:00`, or use the clock button at the right of the field.
    

Emails only go out on the days you selected, between **From** and **To**.

## Step 3: Set the gap between emails

1.  In the **Every** field, enter the number of minutes between emails.
    
2.  Read the line under the field, for example **48 triggers will be sent / day / sender account**. This is how many emails each mailbox can send per day with your window and gap.
    
3.  Make sure **Every** is higher than the **Minimum time gap** set on each mailbox in **Sender Accounts**. If it's lower, sends get skipped and the campaign sends less.
    

A gap under 5 minutes shows the warning: Reducing the time gap less than 5 mins may damage your account reputation. Smartlead also adds a 30 to 60 second variation to each send so the pattern looks natural.

## Step 4: Save your changes

1.  Click **Save Changes** at the bottom of the page.
    
2.  Wait for the message **Settings saved successfully**.
    

On a running campaign, the planned send times are rebuilt straight away with your new days and hours.

## Good to know

-   **The gap must be at least 3 minutes.** A smaller value blocks saving and shows "Minimum time is 3 mins".
    
-   **New Leads/Day is a separate cap.** It sets the maximum number of new leads to contact per day across all email accounts. It is on the same page.
    
-   **Follow-up delays follow your active days.** If you only choose Mon to Fri, weekends don't count toward the wait.
    
-   **Changes made while a campaign is paused apply when you resume it.**
    

## If something goes wrong

**Emails go out outside the days or hours you set**

Cause: the schedule was changed while the campaign was paused, or through the API while it was running. The planned send times were not rebuilt.

1.  Check **Active Days** and **Sending Window** on the **Settings** tab.
    
2.  If you changed the schedule while paused, resume the campaign.
    
3.  If you changed it through the API while the campaign was running, pause the campaign, then resume it.
    

**Save shows "Settings saved, but schedule re-sync failed. Please retry once."**

Cause: the settings saved, but the planned send times could not be rebuilt.

1.  Click **Save Changes** again.
    
2.  If the message returns, pause the campaign, then resume it.
    

**The campaign sends fewer emails than the line under Every shows**

Cause: the mailbox's Minimum time gap is higher than Every, the mailbox is shared with other campaigns, or New Leads/Day is low. See [Issues with the number of emails being sent out](https://helpcenter.smartlead.ai/en/articles/58.md).

Still stuck? Contact support from the chat in your Smartlead dashboard.

## Related articles

-   [How To Create an Email Campaign In Smartlead (the new version)](https://helpcenter.smartlead.ai/en/articles/442.md)
    
-   [Issues with the number of emails being sent out](https://helpcenter.smartlead.ai/en/articles/58.md)
    
-   [My campaign is not sending emails or sending less volume](https://helpcenter.smartlead.ai/en/articles/228.md)