* Don't ignore signed multiparts (and then, now we can see
multipart/signed messages).
pmo-trunk-r4307
header_content_type_lower = header_content_type?g_ascii_strdown (header_content_type, -1):NULL;
if (header_content_type_lower &&
g_str_has_prefix (header_content_type_lower, "multipart/") &&
+ !g_str_has_prefix (header_content_type_lower, "multipart/signed") &&
strstr (header_content_type_lower, "application/")) {
g_free (header_content_type_lower);
g_free (header_content_type);