jmc

The first digit can be any one of 1, 2, 3, 4, 5 or 6. Whatever the first digit is, that fixes what the units digit can be. If we are going to have an even integer, the units digit must be even. This restricts the first digit to 2, 4 or 6. Then, there are 10 choices for the next (thousands) digit. That fixes what the tens digit can be. Finally, there are 10 choices for the third (hundreds) digit. So, we can construct $3\times 10\times 10=\boxed{300}$ palindromes by choosing the digits.