This is actually your answer.
You supplied an empty TO address, because your proberbly supplied a API request to send an outgoing mail which is having incorrect data.
The reopening happens, because the attached error message is an article.
Also, this is good, because this way you’ll see when a mail didn’t go out.
So basically, you’re complaining about a behaviour that shows you that something went wrong.
We can’t help you further with the information provided, sorry.