This an update to information in an earlier post.
Beall’s list of predatory publishers has recently been criticized by Walt Crawford, long-time advocate of Open Access for some biases in what gets listed. Bottom line is journals listed there may or may not be predatory, and journals not listed there also may or may not be predatory – but it’s a good place to do a first check if you’re suspicious.

One of the resources Crawford links to is a good guide to checking the ‘scamminess‘ of publishers posted on Gavia Libraria. The post has very useful tips and considerations and I highly recommend going through the steps provided to check the credibility of a journal before you decide to publish there.