jodd-mail/src/main/java/jodd/mail/CommonEmail.java
public T subject(final String subject, final String encoding) {
		subject(subject);
		this.subjectEncoding = encoding;
		return _this();
	}
public T subject(final String subject, final String encoding) {
		subject(subject);
		this.subjectEncoding = encoding;
		return _this();
	}
Sets message subject with specified encoding to override default platform encoding.
If the subject contains non US-ASCII characters, it will be encoded using the specified charset.
If the subject contains only US-ASCII characters, no encoding is done and it is used as-is.
The application must ensure that the subject does not contain any line breaks.
See {@link javax.mail.internet.MimeMessage#setSubject(String, String)}.

@param subject  The message subject
@param encoding The encoding for the message subject.
@return this