strange characters appear when sending email

Hi again, i face this issue:

part 1: When i send an email from usermin (i send it to my gmail account) in my language(Greek that is) though that i am able to read it in my google account, what i see in my usermin account is this: Subject Έναρξη τη� � εκπαιδευ τικής πλα� �φόρμας τη ς eLearnProject Ltd It appears on the Subject.

part 2:I send an email from my google account and i get this in my usermin account: Yiorgos Katopodis 11/06/2011 04:58 2.55 kB ������ ��� ������������� �� �������� ��� eLearnProject Ltd

Though i am able to read the body of the mail i received the previous one appears in the inbox

part 3: i wrote a message for autoreply using the edit mail and ftp users from virtualmin and when i save it, it looks like this: (& # 917;& # 965;& # 967;αρ& # 953;στ & # 959;ύμ &#949) etc...

and the same thing i receive in my google account

Thanks in advance Yiorgos Katopodis

PS: i made the following modifications i found in a post in the forum:

sed -i /usr/share/usermin/lang_list.txt -e "s/lang=el,/lang=el,charset=UTF-8,/g" sed -i /usr/share/usermin/mailbox/defaultuconfig -e "s/charset=iso-8859-1/charset=utf-8/g" sed -i /usr/share/usermin/mailbox/boxes-lib.pl -e "s/ISO-8859-1/UTF-8/g" sed -i /usr/share/usermin/forward/autoreply.pl -e "s/iso-8859-1/utf-8/g" sed -i /usr/share/usermin/web-lib.pl -e "s/iso-8859-1/utf-8/g"