Indicators of Predatory Conferences
a. The event is organized by a for-profit entity, rather than a credible scholarly or scientific society or association
b. The conference combines a number of fields topics or disciplines into a single conference.
c. The conference uses a free e-mail address, such as Gmail address.
d. The organizers spam prospective attendees to submit proposals and register.
e. Information about who is organizing the conference is either unclear or non-existent; or the organizer is not well known or reputable.
f. Acceptances are promised with a very short turnaround time (often less than four weeks).
g. The conference is marketed as a holiday in a desirable location. The event is held at a resort or a popular tourist destination and marketed as a holiday, rather than an academic or scientific event.
h. The conference name bears a striking resemblance to that of a credible or highly prestigious conference, but has a subtle minor differences in its name.
i. Organizers guarantee contribution will be published as an article in the journal associated with the conference. Like the conference, the journal is also predatory and the organizers may later insist on additional article processing charges to publish your article.
j. The conference websites are unstable. They may change URLs or have no record of conferences in previous years.
k. The website text contains poor grammar or numerous spelling errors.
l. Conference fees seem quite high, compared to those run by non-profit scholarly societies or associations.

Source: Eaton, S.E. (2018). Avoiding Predatory Journals and Questionable Conferences: A Resource Guide. Calgary, Canada: University of Calgary