Dear <co-author's name>,Usually these ridiculous spam requests refer to a paper that has nothing to do with the topic of the journal.
Greetings and good day.
I represent EnPress Publisher Editorial Office from USA. We have come across your recent article “Preface: EmergeNET4: engineering emergence” published in Natural Computing. We feel that the topic of the article is very interesting. Therefore, we are delighted to invite you to publish your work in our journal, entitled Journal of Computer Hardware Engineering. We also hope that you can join our Editorial Board. Please reply to this email if you are interested to join the Editorial Board.
I look forward to hearing your positive response. Thank you for your kind consideration.
Journal of Computer Hardware Engineering
This one refers to the preface to a journal special issue, that has nothing to do with anything other than the rest of that issue!
Yet, somehow, it is so "very interesting" that it entitles me (or maybe just my co-author?) not only to publish in their "journal", but to be on their "Editorial Board".