input: Write a function to validate an email list. The function should return a boolean indicating whether all the email addresses in the given list are valid.
  
  assert validate_mail_list(["example.user@gmail.com", "bad@example"])==False
  assert validate_mail_list(["john.doe@example.com", "user2@example.org"])==True
  assert validate_mail_list([])==True
  assert validate_mail_list(["invalid@email#com", "very.common@example.com"])==False
  assert validate_mail_list(["user@sub.example.com", "user2+plus+tags@example.com"])==True
output: def validate_mail_list(emails):
      import re
      pattern = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
      for email in emails:
          if not re.match(pattern, email):
              return False
      return True