Handle Unicode text, emoji, encoding, normalization, code points, and safe storage.
Lessons
Send multilingual subjects and addresses.
Unicode in Email is easiest to learn by reading the example, changing it, and observing the result.
<?php
// Write a CSV that Excel opens as UTF-8 by adding a BOM
$fh = fopen('export.csv', 'w');
fwrite($fh, "\xEF\xBB\xBF"); // UTF-8 BOM
fputcsv($fh, ['Name', 'City']);
fputcsv($fh, ['José', '東京']);
fclose($fh);
// Without the BOM, Excel often shows "José" (mojibake).Practice the Unicode in Email example in a small scratch file, then explain what changed and why.