Email subject multibyte characters problem while sending email from oracle

Hi

Oracle 12.1.0.2.0

OEL 7.6

I have the following problem.

I want multibyte characters, for example "ä" into email subject.

At the moment the problem is, when I set subject like this:

v_email_subject VARCHAR2(250) := 'Käärid';

I get an email where subject is like this:

Subject: Käärid

My pl/sql code for sending email looks like this:

PROCEDURE SEND_HTML_EMAIL_WITH_ATTACH (p_from IN VARCHAR2, p_to IN ARRAY DEFAULT ARRAY(), p_cc IN ARRAY DEFAULT ARRAY(), p_email_subject IN VARCHAR2, p_message_content IN CLOB, p_attachment_type IN VARCHAR2, p_attachment_name IN VARCHAR2, p_attachment_content IN OUT CLOB)..............g_mail_conn := UTL_SMTP.open_connection(MONITOORINGUPAKK.SMTP_SERVER_NAME, MONITOORINGUPAKK.SMTP_SERVER_PORT);