Malformed UTF-8 character (unexpected non-continuation byte 0x6e, immediately after start byte 0xf6) in transliteration (tr///) at /data/masscheckwork/weekly_mass_check/masses/../lib/Mail/SpamAssassin/DnsResolver.pm line 627.
On a second thought, this should never have happened. It indicates that something has flagged a string as a character string (uft8 flag on) without checking its contents or using Encode::convert to decode bytes to strings. This should be investigated, it is not something that DNS resolver should try to work around, such a string should never have been produced at all. What version of Perl was that? Was the setting normalize_charset turned on? Mark