What are the limitations of using regular expressions for email validation in PHP, especially with regards to international characters?

Regular expressions for email validation in PHP may not properly handle international characters, such as accented letters or characters from non-English languages. To address this limitation, it is recommended to use PHP's built-in filter_var function with the FILTER_VALIDATE_EMAIL filter, which has better support for international characters in email addresses. 

$email = "example@éxample.com"; // Email with international characters

if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
    echo "Valid email address";
} else {
    echo "Invalid email address";
}

Keywords

regular expressions email validation limitations international characters PHP

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