The wrong version of an Account Engagement email was sent

This can be a result of:
 

When an edit session is closed, it won't permeate to other open sessions. So, if working in two windows, it's possible that a change in one could be overwritten by another session. The timeline would look something like this: 

Because of this, we recommend doing all edits in a single browser window if possible. Take extra care to save and exit any edit session before starting a new one. If you find an open session that is older than an update that was made in another window, you can cancel out of that session, ensuring it doesn't overwrite your changes. 

Keep in mind this is only referring to a single user editing in multiple windows. Account Engagement will not allow multiple users to edit the same email. 

When copying or editing emails, it is very common that we forget to also edit/update the text version, resulting in two completely different emails being sent. Your reporting gets messy due to this, especially, when there are links that were supposed to be changed but did not. So, ensure that when copying or editing an email, you also update the text version of it.

To check if you have the latest version of your text version, you can edit the email you have drafted and go to the text version to compare it with the HTML version.