Autoresponder Emails Subject Charset UTF8 Problem

Hi there.

I love Virtualmin Software but I am struggling to find a way to display Greek characters in the autoresponder email subjects.
If an autorespond message is sent with greek characters in the subject, then ithey are displayed as dummy characters.

I have updated webmin to 1.900, I confirm that webmin and usermin locale settings are set to (EN.UTF-8) but the headers of the message show that the email headers are using Content-Type: multipart/mixed; boundary=“bound1551XsomenumbersX”, Content-Transfer-Encoding: 8bit"

i really need to send the autoreply headers using UTF-8 character encoding in order to be able to support greek characters.

How is this possible?

I also have found another topic that says that the bug is fixed. You can see it below

This is the old topic link.

Please let me know if I am doing something wrong.

Operating system and other info:
CentOS Linux 7.4.1708
Webmin version 1.900
Usermin version 1.734
Virtualmin version 6.02
Authentic theme version 19.21