def check_email(string):
    if ' ' not in string and '@' in string and '.' in string:
        index_symbol = string.index('@')
        index_dot = string.find('.', index_symbol)
        if -1 < index_dot > index_symbol + 1:
            return True
    return False

b83d2c8683d951e1964a4cd52a20adccc653d640
<mask token>

def check_email(string):
    if ' ' not in string and '@' in string and '.' in string:
        index_symbol = string.index('@')
        index_dot = string.find('.', index_symbol)
        if -1 < index_dot > index_symbol + 1:
            return True
    return False
