[Gpg4win-users-en] How to get GnuPG using UTF-8 strings for attachment names

[Alexander Strobel]

Hello, 

when i send an attachment mit german umlauts in its name, they are not shown at the recipient. The umlauts are on the recipients side shown as questionmarks.
The other way round it is not a problem. The umlauts are shown correctly.
I am using Thunderbird 12 with OpenPGP/Enigmail 1.4.2 on Windows 7. The recipient is using Symantec PGP Desktop 10. (He is using Windows 7, too.)

I did take a look with --list-packets at the attachments and found out, that Enigmail creates a filename "\xdcmlauts.txt" while PGP Desktops encodes it as "\xc3\x9cmlauts.txt" .
A search on Google told me, that this probably has something to do with utf-8 encoding, but I could not find any information about how to force utf-8 encoding when creating a mail in openPGP.
Can someone show me how to do this?

Thanks in advance
Alex