Problem with Attachments including German Umlaute in filename

Hi RT Users,
during the weeks, we got more and more reports from our users, that mails sent to RT (RT 3.6.5) have corrupted file attachments. RT stores and displays them as .dat file.

I’ve played around a little and figured out, only Files with german umlaute in filename have this problem. I’m not sure where to start to fix this at this moment.

as example i create a mail with the following files attached:

apple iMer.jpg -> no problem
apple_iMer.jpg -> no problem
apple_üMer.jpg -> problem

Inside the RT History the file looks like this:

Download apple iMer.jpg [image/jpeg 7k]
Download apple_iMer.jpg [image/jpeg 7k]
Download (untitled) [name="apple_ 7k] Message body not shown because it is too large or is not plain text.

I have really no idea at this moment where to start trouble shooting. Any help is welcome.

Thanks

Torsten

Kühne + Nagel (AG & Co.) KG, Geschäftsleitung: Hans-Georg Brinkmann (Vors.), Uwe Bielang (Stellv.), Bruno Mang, Dirk Blesius (Stellv.), Alfred Manke, Christian Marnetté (Stellv.), Mark Reinhardt (Stellv.), Jens Wollesen, Rainer Wunn, Sitz: Bremen, Registergericht: Bremen, HRA 21928, USt-IdNr.: DE 812773878, Persönlich haftende Gesellschaft: Kühne & Nagel A.G., Sitz: Contern/Luxemburg Geschäftsführender Verwaltungsrat: Klaus-Michael Kühne