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--- a/src/internfile/mh_mbox.cpp
+++ b/src/internfile/mh_mbox.cpp
@@ -57,6 +57,7 @@
 bool MimeHandlerMbox::set_document_file(const string &fn)
 {
     LOGDEB(("MimeHandlerMbox::set_document_file(%s)\n", fn.c_str()));
+    RecollFilter::set_document_file(fn);
     m_fn = fn;
     if (m_vfp) {
 	fclose((FILE *)m_vfp);