From ac96fa389eaf204ed096abfe90f8f0e6e2ad0e4f Mon Sep 17 00:00:00 2001
From: Oskar Eichler <62393985+OskarEichler@users.noreply.github.com>
Date: Sun, 30 Aug 2026 14:56:19 +0700
Subject: [PATCH] Reset SMTP capabilities around connection attempts

---
 lib/net/smtp.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/net/smtp.rb b/lib/net/smtp.rb
index cca06e6..ff2019c 100644
--- a/lib/net/smtp.rb
+++ b/lib/net/smtp.rb
@@ -668,6 +668,7 @@ def do_start(helo_domain, user, secret, authtype)
       if user || secret || authtype
         check_auth_args authtype, user, secret
       end
+      @capabilities = nil
       s = Timeout.timeout(@open_timeout, Net::OpenTimeout) do
         tcp_socket(@address, @port)
       end
@@ -691,6 +692,7 @@ def do_start(helo_domain, user, secret, authtype)
         # authentication failed, cancel connection.
         s.close if s
         @socket = nil
+        @capabilities = nil
       end
     end