[otrs] Malformed UTF-8 character in procmail-2005-08 log

I get this error if anyone sends an mail to otrs. Malformed UTF-8 character (unexpected non-continuation byte 0xdf, immediately after start byte 0xfc) in substitution (s///) at /opt/otrs/Kernel/System/Ticket/Article.pm line 101. If I reply and he/she sends angain, this error is not logged. What can this be?? --------------------------------- Gesendet von Yahoo! Mail - Jetzt mit 1GB kostenlosem Speicher