input: Write a function to validate a list of emails. The function should return a boolean indicating whether a given email address is valid. If the given list is empty then return True.
  def validate_mail_list(mail_list):
      for mail in mail_list:
          if not re.match("[^@]+@[^@]+\.[^@]+", mail):
              return False
      return True
  
  assert validate_mail_list(["example.user@gmail.com", "bad@example"])==False
  assert validate_mail_list(["valid.email@gmail.com", "another.valid@domain.com"])==True
  assert validate_mail_list(["invalid-email@", "another@invalid"])==False
  assert validate_mail_list([])==True
  assert validate_mail_list(["email.only@domain"])==False
output: 
  def validate_mail_list(mail_list):
      for mail in mail_list:
          if not re.match("[^@]+@[^@]+\.[^@]+", mail):
              return False
      return True
  