How to fix cracks in outgoing emails?

Question

JavaScript

AddEventHandler("iblock", "OnAfterIBlockElementAdd", Array("OnAfterArticleAdd", "OnAfterIBlockElementAddHandlerLast"));
class OnAfterArticleAdd {
   function OnAfterIBlockElementAddHandlerLast(&$arFields) {
      if ($arFields["IBLOCK_ID"] == 26 && $arFields["RESULT"]>0) {
$message .= 'Свойство 1: '.$arFields['PROPERTY_VALUES']['FIO'];
         mail('[email protected]', 'Добавлен отзыв на сайт', $message, $headers);
      }
   }
}

At the output we have:
Свойство 1: Антон
i.e. the first part is norm-coded, but the second part (the one with $arFields['PROPERTY_VALUES']['FIO']) is not.
How to fix?

Answer 1

I think the problem is here:

fs.writeFile(fullPath, base64Image, { encoding: 'base64' }, err => {
            if (err) return res.status(500).send(`Ошибка сохранения файла: ${err}`)
            else return
        });

because after this piece of code, without waiting for the result, the following code is executed. Thus, it is possible that send in this piece of code will be executed after send in the following code,
try replacing this code with:

const promise = new Promise(resolve, reject)=>{
   fs.writeFile(fullPath, base64Image, { encoding: 'base64' }, err => {
      if (!err) return resolve(true);
      
      res.status(500).send(`Ошибка сохранения файла: ${err}`)
      return reject(false);
   });
});
const isWrite = await promise;
if(!isWrite) return;

Answer 2

php.net/manual/ru/function.mb-convert-encoding.php
something like this, play around with the second parameter of the function, perhaps a different encoding will be needed there.

Answer 3

So to speak, "temporarily rewound with tape":
Well, or just make sure that the array "comes" not in 1251, but immediately in utf8

Answer 4

There is already a built-in functionality for working with mail events. Use it.
Link