Hi, More bad news, I'm afraid: MIME-Tools does NOT support RFC 2231 (see ftp://ftp.isi.edu/in-notes/rfc2231.txt). It will require a fair bit of work to modify it to support that RFC; I hope to have a release by the end of next week. In the mean time, filename-based checks could fail if rfc2231 encoding is used. Regards, David.