How can I set rules to prevent “good” emails ending up in the Junk Mail? I have missed some quite important messages because they had been put into the Junk Mail box.
Messages are normally moved to the Junk folder by your email server and not eM Client, and once your server has moved them, there is nothing in eM Client that will move them out of the Junk folder automatically.
Your email provider should offer some way to disable spam filtering, or to mark messages as NOT Spam.
eM Client is also able to move messages to Junk, but only if you have added the sender’s email address or domain to a Blacklist. Go to Menu > Rules, and if there is a Blacklist Rule there, edit it and remove this sender’s email address or domain.