Is there a with list in eM Client. If so. Where can i find it
eM Client has no spam detection ability, so has no need for a whitelist.
If you have added an email address or domain to your Blacklist by mistake, just edit the Blacklist Rule and remove it. Otherwise the messages will be moved to spam by your server. Once your server has moved a message to spam, eM Client Rules will not move them out of spam again. But you can login to webmail for your email provider and mark the messages as not spam, or they may have a whitelist option to prevent named addresses from going to spam.