Outboundcharset does not applied.

Hi, everyone.

I'm JS.

I have a big trouble about utf8 setting.

We have installed Exchange Server 2013 sp1 with dag.
And we have to apply OutboundCharset for AlwaysUTF8.

I tried to apply using cmdlet as below.

Set-OwaVirtualDirectory -identity "SERVER1\owa (Default Web Site)" -OutboundCharset AlwaysUTF8

Set-OwaVirtualDirectory -identity "SERVER2\owa (Default Web Site)" -OutboundCharset AlwaysUTF8

Set-OwaVirtualDirectory -identity "SERVER1\owa (Exchange Back End)" -OutboundCharset AlwaysUTF8

Set-OwaVirtualDirectory -identity "SERVER2\owa (Exchange Back End)" -OutboundCharset AlwaysUTF8

And

iisreset /noforce

Server reboot.

Re construct VirtualDirectory.

But... it is not working.

Server's response shows OutboundCharset : AlwaysUTF8
But actually all eml files are not UTF8.

Please help me... How can I do?