Problem with Content-Transfer-Encoding and Content-Type in the email header

[Guilhermehsa]

On two different Directadmin servers installed in the same way, different encodings are displayed when checking the email header. I wanted to leave it in utf8 and 8bits as it happens on server 2, but server 1 for some reason is different:

Server 1

Content-Type: multipart/alternative;
boundary="=_e8f97cefb2106e5a4d976e71a8bdfb81"

--=_e8f97cefb2106e5a4d976e71a8bdfb81
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII;
format=flowed

dfsadfsadfsadfsa
--=_e8f97cefb2106e5a4d976e71a8bdfb81
Content-Transfer-Encoding: quoted-printable
Content-Type: text/html; charset=UTF-8

-----------------------

Server 2

Content-Type: multipart/alternative;
boundary="=_db34fad322fb5c040c82fc23fbc9394d"

--=_db34fad322fb5c040c82fc23fbc9394d
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=UTF-8;
format=flowed

ÃÉÉÉÉÉÉÃÃÃÃÉÉÉÉ´aÃÃÃaÃÃÃÃÃÃ
--=_db34fad322fb5c040c82fc23fbc9394d
Content-Transfer-Encoding: quoted-printable
Content-Type: text/html; charset=UTF-8

=================

In other words, how do I make in a DirectAdmin server 1 have the parameters below:

Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=UTF-8

[alec]

Why? If the content is ASCII the UTF8 charset doesn't change anything, encoding neither.

Preferences > Composing Messages > Use MIME encoding for 8-bit characters - may be related.

[Guilhermehsa]

Hello, thanks for the feedback.

I'm facing a character encoding problem on a server.

In it, if the message through roundcube is written in HTML format, characters like "áéíóúiã..." simply disappear from the message body even though they are still present in the subject.

Analyzing another server that doesn't have this problem, I noticed this difference and wanted to try adjusting this to see if it would solve the problem, but I couldn't find a way to apply this type of adjustment.

[Guilhermehsa]

That is, basically the same problem reported in:

https://www.roundcubeforum.net/index.php/topic,30728.msg77913.html#msg77912