+/* Construct the list of domains from the ARC chain after validation */
+
+uschar *
+fn_arc_domains(void)
+{
+arc_set * as;
+gstring * g = NULL;
+
+if (!arc_state || Ustrcmp(arc_state, "pass") != 0)
+ return US"";
+
+for(as = arc_verify_ctx.arcset_chain; as; as = as->next)
+ {
+ blob * d = &as->hdr_as->d;
+ g = string_append_listele_n(g, ':', d->data, d->len);
+ }
+return g ? g->s : US"";
+}
+
+