extern uschar *string_domain_alabel_to_utf8(const uschar *, uschar **);
extern uschar *string_domain_utf8_to_alabel(const uschar *, uschar **);
extern uschar *string_localpart_alabel_to_utf8(const uschar *, uschar **);
extern uschar *string_domain_alabel_to_utf8(const uschar *, uschar **);
extern uschar *string_domain_utf8_to_alabel(const uschar *, uschar **);
extern uschar *string_localpart_alabel_to_utf8(const uschar *, uschar **);