Horror Tree: https://horrortree.com/events/list
Published To Death: https://publishedtodeath.blogspot.com/p/calls-for-submissions.html
The Submission Grinder: https://thegrinder.diabolicalplots.com
Submittable Discover: https://discover.submittable.com
New Pages: https://www.newpages.com/submission-opportunities/calls-for-submissions
Chill Subs: https://www.chillsubs.com/browse