Q: Whom should I send my e-mail submission to if the journal does not have a specific person in charge of submissions?

I can understand your problem. The submisssion process can be difficult for authors if the journal does not provide clear instructions.

Have you gone through the journal’s website carefully? Ideally, you should send your paper to the Editor-in-Chief or Chief Editor. However, since there are two Chief Editors in this case, it is even more confusing for you. Go through the journal’s website once again. Sometimes, the journal assigns certain specialty areas or fields to each Chief Editor. So check if there are any clear instructions stating that papers related to a particular subject should be sent to a specific editor. Sometimes, Chief Editors are also assigned according to geographical locations. For instance, papers from Asia could be assigned to a specific editor while papers from the rest of the world could be assigned to another. If you do not find any instructions of this sort, you can address the cover letter to both the Chief Editors, for example, “Dear Mr. A and Mr. B” or “Dear Chief Editors.”

Regarding your second question, this varies from journal to journal. Some journals have clear policies and guidelines such as the ones I mentioned above. Others, unfortunately, do not have any such clear processes in place.