sfEmailValidator、どう見ても$strict == trueの方が判断ゆるくね？
バグ？

strictの時：
$re = '/^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i';

strictじゃない時：
$re = '/^([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-'
.'\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80-\\xff]|\\x5c\\x00-'
.'\\x7f)*\\x22)(\\x2e([^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-'
.'\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x22([^\\x0d\\x22\\x5c\\x80'
.'-\\xff]|\\x5c\\x00-\\x7f)*\\x22))*\\x40([^\\x00-\\x20\\x22\\x28\\x29'
.'\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+|\\x5b([^'
.'\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c\\x00-\\x7f)*\\x5d)(\\x2e([^\\x00-'
.'\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-'
.'\\xff]+|\\x5b([^\\x0d\\x5b-\\x5d\\x80-\\xff]|\\x5c\\x00-\\x7f)*'
.'\\x5d))*$/'