Score on mail-tester.ru 4.7, what should I do?

Question

Email

Hello, I passed the test on the site mail-tester.ru and got a score of 4.7. To be honest, I have already gone through a lot of options: I changed hostings, wrote a bunch of texts, but still I did not rise above 4.7. In SpamAssasin it gives the following:
The famous SpamAssassin spam filter. Rating: -4.3.
A score below -5 is considered spam.
-0.001 HTML_MESSAGE HTML included in message
Don't worry we're expecting an HTML version of the mail message
-1.996 MIME_HEADER_CTYPE_ONLY 'Content-Type' found without required MIME headers
-1.105 MIME_HTML_ONLY Message only has text/html MIME
parts text/plain)
0.001 SPF_HELO_PASS SPF: HELO matches SPF record
0.001 SPF_PASS SPF: sender matches SPF record
Great! Your SPF is valid
-0.1 SUBJECT_NEEDS_ENCODING Subject is encoded but does not specify the encoding
-1.105 SUBJ_ILLEGAL_CHARS Subject: has too many raw illegal characters
What needs to be corrected in the text, please tell me.

Answer 1

MIME_HEADER_CTYPE_ONLY
The email has a Content-Type header but no accompanying headers. Add the MIME-Version and/or Content-Transfer-Encoding header with the correct values.
If the letter contains an HTML part, it is recommended that it contain a PLAIN part similar in content. Make a multipart letter.
Only 7-bit ASCII characters are allowed in headers. All other characters must be encoded, for example through Base64. In the body of the letter, all characters must match the encoding specified in the Content-Type header.

Answer 2

Nothing, spamassassin indicates that there is too much html in the body and too little text.
there are wrong characters in the subject of the letter ... all this is nonsense.
You are trying to adapt to someone else's server with your own settings, you don't need to do this.
Everything is normal in your letters, do not worry. The test to Yandex and Google passes? If yes, then exhale and continue tuning.