After an email (e.g., Email Broadcast, Email Sequence email, Event email, or an Automation email) has been sent, the email can not be changed.
Note:
Emails in an Email Sequence can be updated for new sequence subscribers. In the same way, emails surrounding an event or email sent from an Automation can be edited for future recipients. However, you cannot retroactively edit an email for recipients that have received the email. Learn to edit emails in an email sequence
Although a sent email cannot be edited, you can clone the sent email to send an updated version to your recipients:
When crafting your email campaigns be sure to finalize, preview, and test your emails before sending. Learn to test send your emails
