Why is the same email displayed differently in Outlook and Thunderbird?

Question

Character encoding

Good afternoon,
In addition to my question here: Why does the encoding get lost in Outlook?
We received one letter, judging by the headers - everything is correct, UTF-8. But in Outlook 2010 SP2 with the latest updates and Outlook 2013 SP1, the letter is displayed crookedly, although the client has correctly determined the encoding.

The same letter is displayed correctly in Thunderbird, it also determines the encoding in UTF-8:

Where else can I look? I'm currently upgrading Exchange to RU11, but it seems to me that the problem is still in the MUA (Outlook).

Answer 1

The MTA does not rewrite the letter (at least it shouldn't). It all depends on who sent the letter.