function extractEmails(input) {
   const mailValidation = /(^|(?<=\s))(([a-zA-Z0-9]+)([\.\-_]?)([A-Za-z0-9]+)(@)([a-zA-Z]+([\.\-][A-Za-z]+)+))(\b|(?=\s))/gmi
   let matches = mailValidation.exec(input);

   while (matches !== null) {
     console.log(matches[0]);
     matches = mailValidation.exec(input);
   }
 }

 extractEmails(
   'Many users @ SoftUni confuse email addresses. We @ Softuni.BG provide high-quality training @ home or @ class. –- steve.parker@soft-uni.de.'
 );