Apex Email Error - INVALID_EMAIL_ADDRESS, Invalid to address

Try validating cc and bcc addressess by checking null or empty

  if(emailCCAddress != null && emailCCAddress.trim() != ''){
        Ccaddress = emailCCAddress.split(',',0);
        mail.setCcAddresses(ccaddress);
        }
  if(emailBCCAddress != null && emailBCCAddress.trim() != ''){
        Bccaddress = emailBCCAddress.split(',',0);
        mail.setBccAddresses(Bccaddress);
        }