Description
Several factors influence the time required for a campaign to be delivered, including list size, server speed, and others. Progress indicators are available for all campaigns under the Campaign Outbox, so you can monitor delivery in real time.
Why it's important
It ensures your messages reach contacts at the most appropriate moment, while giving you visibility into the sending process, helping you quickly detect, investigate, and resolve any potential deliverability issues before they affect your results.
Factors affecting delivery speed
Several factors can influence email delivery times:
Technical factors:
- List size: Larger lists take more time to process and deliver
- Server speed: Server performance affects processing time
- Network conditions: Internet connectivity and network traffic
- Email volume: High-volume sending periods can cause delays
External factors:
- Recipient server load: Receiving email servers may throttle incoming messages
- ISP policies: Different email providers have varying acceptance rates
- Time of day: Peak sending hours can result in slower delivery
- Content analysis: Anti-spam filtering processes can add processing time
Monitor your campaign delivery
Real-time tracking:
- Campaign Outbox: Progress indicators show delivery status
- Real-time updates: Monitor delivery in real time
- Delivery statistics: View completed vs. pending deliveries
What to expect:
- Small lists (under 1,000): Generally delivered within minutes
- Medium lists (1,000-10,000): May take 30 minutes to several hours
- Large lists (10,000+): May take several hours depending on various factors
When to contact support
If you believe your campaign should have been delivered already or an error has occurred, let us know.
Signs of delivery problems:
- Campaign stuck in outbox for an unusually long time
- Error messages in delivery status
- Significant delays beyond expected timeframes
- Incomplete delivery without apparent cause
Best practices for faster delivery
- Authenticate your domain: Properly authenticated domains often get priority
- Maintain list quality: Clean lists with low bounce rates process faster
- Optimize sending times: Avoid peak hours when possible
- Monitor performance: Regular monitoring helps identify issues early
Troubleshooting
My campaign has been stuck in the outbox for hours
- Check if your account is under review or suspended
- Verify that your sending limits have not been exceeded
- Look for error messages in the campaign status
- Contact support if the campaign hasn't moved after 4 hours
Some recipients received emails while others did not
- Different ISPs process emails at different speeds
- Check if delayed recipients are from specific domains (Gmail, Yahoo, etc.)
- Verify that these addresses haven't bounced or unsubscribed
- Large providers may throttle delivery during peak hours
Delivery is much slower than usual
- Compare current list size to previous campaigns
- Check if you're sending during peak hours (9-11 AM, 2-4 PM local time)
- Verify that your domain authentication is still valid
- Consider if recent poor engagement metrics are affecting delivery speed
How to speed up future deliveries
- Send to engaged subscribers first (opened within the last 90 days)
- Split large lists into smaller segments sent at different times
- Avoid sending during typical peak hours when possible
- Maintain good list hygiene to reduce processing of bad addresses
Related articles
- Troubleshooting missing emails - Related issue
- Mastering deliverability basics - Improve delivery speed
- Understanding campaign reports - Track delivery times
- Managing under review warnings - Cause of delay
- Testing your campaign - Test delivery