Thank you for your message, I looked at the documents you sent. First of all, I could not find the setting section for the following section in OJS 3.3.0-16.
Secondly, sometimes the system appears to have sent an email, but the email server does not send an email out due to an internal error, but it sends the related copy email to the address into the server. Therefore, if a copy of all messages is sent to an address such as managing@eurjchem.com, we can forward this message to the recipients when necessary.