I constantly receive emails from editors asking me to submit papers for their journals. 

However, only a handful of them originate from a trustworthy source. The vast majority is just scam — journals with no reputation at all, willing to charge a fee to publish an article.

My biggest problem with that is that I lost one or two real good opportunities to publish because I dismissed the email, thinking it was a scam.

Is there a list which I can easily check the reputation of a journal, in order to avoid this to happen?