From 9df88745dc30f7f462fd8c3fce5d8a2379fde466 Mon Sep 17 00:00:00 2001
From: Alexander Krotov <ilabdsf@gmail.com>
Date: Sun, 15 Nov 2020 22:39:54 +0300
Subject: [PATCH] smtp: do not use STARTTLS when PLAIN connection is requested

Also do not allow downgrade if STARTTLS is not available
---
 src/smtp/mod.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/smtp/mod.rs b/src/smtp/mod.rs
index 873f2b1a7..14cfa2889 100644
--- a/src/smtp/mod.rs
+++ b/src/smtp/mod.rs
@@ -192,7 +192,8 @@ impl Smtp {
         };
 
         let security = match lp.security {
-            Socket::STARTTLS | Socket::Plain => smtp::ClientSecurity::Opportunistic(tls_parameters),
+            Socket::Plain => smtp::ClientSecurity::None,
+            Socket::STARTTLS => smtp::ClientSecurity::Required(tls_parameters),
             _ => smtp::ClientSecurity::Wrapper(tls_parameters),
         };