If you're not sure if a publisher is legitimate or predatory, be on the watch for the following red flags:
After Jeffrey Beall took down his list of predatory journals in January 2017 in order to avoid continued harassment and threats, a small group of scholars and information professionals decided to anonymously rebuild and resurrect that list.
This is available via:
Beall's List : a list of questionable, scholarly, open access publishers.
Think, Check, Submit, provides a simple assessment framework to help scholars identify trustworthy journals.