Add a new action "Log to history list" after the email action:
Then we will see the information in workflow history if the email has been sent:
Per my test I could receive the email successfully:
Make sure you have configured outgoing email at farm level(Central Administration> System settings> Configure outgoing email) and the web application level(Central Administration> Manage web applications>select the web application> General settings>Outgoing E-mail ), and the related exchange server works well.
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