There could be a few reasons for an email getting stuck in "WFA" or "Waiting for Approval". It could be due to a rule set in place that requires emails to be manually approved first, replacement codes (e.g., "Hi [NAME]!") that are not working properly, or the sender not having email sync enabled.

If it gets stuck in the Gmail/Outlook server, it could be due to a variety of reasons but the common ones include replacement code(s) error, incorrect recipient email address, attachment size too large, etc.

You can check in the WFA folder on the email itself, as there will be an error message on the right stating the reason for that particular email landing in the "Waiting for Approval" folder. This will help you identify the reason so that you can action it, and allow for it to then successfully be processed to send!