Hi @george12345245135124 - thank you for asking your question in the Klaviyo Community! 

Can you please provide a bit more information about your scenario? Perhaps share a screen shot of the detail/status page for this campaign?

Also, a few follow-up questions and/or potential causes: 

• Is this campaign set to “Gradual send over several hours”?
• Is this campaign set to send via Recipient’s Local Timezone?

If you created this email as a campaign (not a flow), then this email should not send to anyone outside of the recipient list that was confirmed at the time of send. 

Hey @george12345245135124 , this could be happening due to a number of reasons. For example:
 

1. A large number of recipients: Your campaign is being sent to a large number of people, and Klaviyo’s smart enough to not send them all instantly (because it can be flagged by the ESP as shady behavior and potentially hurt your domain reputation)

2. Campaign settings: If the campaign settings are not configured correctly, it could cause delays in the sending process. For example, if the campaign is set to send at a specific time but the time zone is not correctly set, it could cause the campaign to be delayed. Also, If for example, you sent the campaign to send at 10am of the Recipients Local time zone, the campaign will deploy in buckets and you’d see contacts in queue if their time zone had not reached the scheduled time for the campaign.

3. Delivery issues: Some emails may have failed to deliver due to issues with the recipient's email server or because the email was marked as spam, which could cause the campaign to be delayed. This can happen if you haven’t cleaned your list in a while.

The best course of action would be to wait patiently for 24hrs, and then investigate for any potential issues.