Unreadable emails, Incorrect display of emails?

Question

Microsoft Exchange

Good afternoon! I will make a reservation right away, I am not a Bitrix administrator and not a developer. I was instructed to look into the problem, but for the life of me, I can’t figure out which end the problem is on.
Essence:

1. Exchange 2016 mail server,
   
2. Bitrix in UTF-8 encoding,
   
3. Letters are typed with

   <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>

   
   
4. The parameter in the main module settings (Convert 8-bit characters in the message header) is set to
   
5. Outlook 2016 client
   
6. Letters/notifications from Bitrix come in an unreadable form. Those. the subject of the letter is normal, but the body of the letter is sloppy. I look at the encoding of the letter - UTF-8.
   
7. Tell me where to dig? Somehow it turns out dually: the topic is normal, the text is unreadable.