tx aet
https://gist.github.com/turkerali/f87d77b6cb64061f2aa459b4590a1348
https://marc.info/?l=qmail&m=118763997501287&w=2

--- netqmail-1.06-original/qmail-smtpd.c
+++ netqmail-1.06/qmail-smtpd.c
@@ -40,6 +40,7 @@
 void tls_nogateway();
 int ssl_rfd = -1, ssl_wfd = -1; /* SSL_get_Xfd() are broken */
 int forcetls = 1;
+stralloc proto = {0};
 #endif
 
 /* start chkuser code */
@@ -2118,7 +2119,20 @@
     case 0:
       if (!spp_auth(authcmds[i].text, user.s)) return;
       seenauth = 1;
+#ifdef TLS
+      if (ssl) {
+        if (!stralloc_copys(&proto, "ESMTPSA (")
+            || !stralloc_cats(&proto, SSL_get_cipher(ssl))
+            || !stralloc_cats(&proto, " encrypted, authenticated)")) 
+          die_nomem();
+        if (!stralloc_0(&proto)) die_nomem();
+        protocol = proto.s;
+      } else {
+        protocol = "ESMTPA";
+      }
+#else
       protocol = "ESMTPA";
+#endif
       relayclient = "";
       remoteinfo = user.s;
       if (!env_unset("TCPREMOTEINFO")) die_read("TCPREMOTEINFO not set");
@@ -2140,7 +2154,6 @@
 }
 
 #ifdef TLS
-stralloc proto = {0};
 int ssl_verified = 0;
 const char *ssl_verify_err = 0;