Question marks appear in arabic emails

Why do question marks appear within the address of the mail messages as explained by the facility?
 Use the Arabic language in the store

If it's not in the translation it could be some email header missing for displaying content correctly?
https://github.com/litecart/litecart/blob/dev/public_html/includes/entities/ent_email.inc.php#L150-L151

The translation is correct, and I checked what is mentioned in the link. Things are good and the situation is still the same.

Can you view the raw email source text and confirm the issue is in the raw email as well and not just the client?

Thanks for your interest, but how?

In Gmail it's Open message > select three dots > Show Original.

Yes, there

It is clear that it is a problem related to the language in general and not only my location and in the picture when sending an verification code.

Did the raw email data also show question marks?

yes

First make sure your storage encoding is set to a charset and collation that supports arabic.
Admin -> Language -> Storage Encoding. You can try utf8mb4_0900_ai_ci. This is to ensure that emails stored in the database does not lose character data.

Current preparation "utf8mb3_unicode_ci" and this option is not available 'utf8mb4_0900_ai_ci"in the list

As I mentioned, even the verification message that reaches my pillow from the forum here has a mark "?" This means it is not only for my site
For the code of the symbol in the title of the message only, as for the content, it appears well

I have addressed [b]mb_encode_mimeheader() [/b]to be the cause of the problem with the subject.
https://github.com/litecart/litecart/blob/2.6.0/public_html/includes/entities/ent_email.inc.php#L308

Make sure you have these 3 lines in your includes/config.inc.php:

 mb_internal_encoding('UTF-8');
 mb_regex_encoding('UTF-8');
 mb_http_output('UTF-8');```

See the docs if you can add mb_language() as well to config.
https://www.php.net/manual/en/function.mb-language.php

I am clueless what to do as I can confirm the issue here as well, and I have set internal encoding.
We are using the recommended way to encode a subject in PHP.
https://stackoverflow.com/questions/9089586/php-email-with-arabic-characters

ليست لغة نظام 
Not a system language

See the "م" I am sure it will appear as question mark 
and don't ask me why, I just don't know

Let's try it now

I added the three lines and it was useless. To see the problem yourself, you can log out here and change the language to Arabic and log in from a different device and wait for the verification code. You will find the message title contains the symbol "?" while the message inside is intact.

As the brother mentioned ecs .
It is related to one letter in the Arabic language, which is the letter "م" the following sentence
ت? استخدا? اس? ?ضيف ?ختلف لتسجيل الدخول إلى حسابك (ت؟ استخدا ؟ اس ؟ ?ضيف ?مختلف لتسجيل الدخول إلى حسابك)
It is supposed to appear like this
تم استخدام اسم مضيف مختلف لتسجيل الدخول إلى حسابك.
Knowing the letter appears seriously inside the site and the same problem is the letter appears with the upcoming mail messages from info@litecart.net If the Arabic language is determined before logging in