Email Marketing: Email Throttling

2 min read
If you send an email campaign and notice some contacts haven't received it, make sure that your recipient list is updated and maintained. If there are issues with spam complaints or emails bouncing back, it could result in a slowed campaign distribution known as 'email throttling'.

What is email throttling?

Email throttling is part of an email marketing abuse detection system used to identify spam or harmful campaigns. When you send a campaign, the system reviews it for potential issues or harmful content. 

These issues include:
  • A large chunk of emails bouncing back to the sender
  • Multiple complaints or reports of spam 
  • Emails falling into spam-traps and hitting spam folders
  • Little to no engagement from your email list 

If the abuse detection system finds an issue with your campaign, it slows the rate at which the campaign is distributed and delivered to your recipients. The deliberate slowdown of email distribution in order to prevent potential spam is known as 'email throttling'. 

How email throttling affects your campaign

Email throttling protects your contacts from spam by checking the responses from the first batch of campaign recipients before potentially decreasing the emails sent in the second batch. In some cases, email throttling can also cut off distribution altogether. 

This means if your contact list is full of the issues mentioned above, some recipients may not receive your campaign for 24 or even 48 hours. If the system notices issues still occurring, even after the email throttling, it can end the campaign altogether. Any emails remaining in the queue will not be sent. 

What can I do about email throttling?

As long as your contact list is maintained and updated regularly, you should be fine. 

Make sure you are following email marketing best practices like:
  • Getting explicit consent from every recipient to send them emails
  • Not including any suspicious or prohibited content
  • Cleaning your list every six months to make sure all its email addresses are still valid
View a full list of Wix Email Marketing best practices for more helpful tips on sending your campaigns. 

Did this help?