diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Config.php b/rainloop/v/0.0.0/app/libraries/MailSo/Config.php
index 8487235ce..dd35cac57 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Config.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Config.php
@@ -44,10 +44,15 @@ class Config
 	public static $MessageListDateFilter = 0;
 
 	/**
-	 * @var int
+	 * @var bool
 	 */
 	public static $LogSimpleLiterals = false;
 
+	/**
+	 * @var bool
+	 */
+	public static $PreferStartTlsIfAutoDetect = true;
+
 	/**
 	 * @var \MailSo\Log\Logger|null
 	 */
diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Net/Enumerations/ConnectionSecurityType.php b/rainloop/v/0.0.0/app/libraries/MailSo/Net/Enumerations/ConnectionSecurityType.php
index 43fd82b38..bdf4e2f56 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Net/Enumerations/ConnectionSecurityType.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Net/Enumerations/ConnectionSecurityType.php
@@ -54,7 +54,8 @@ class ConnectionSecurityType
 	public static function UseStartTLS($bSupported, $iSecurityType, $bHasSupportedAuth = true)
 	{
 		return ($bSupported &&
-			(self::STARTTLS === $iSecurityType || (self::AUTO_DETECT === $iSecurityType && !$bHasSupportedAuth)) &&
+			(self::STARTTLS === $iSecurityType || 
+				(self::AUTO_DETECT === $iSecurityType && (!$bHasSupportedAuth || \MailSo\Config::$PreferStartTlsIfAutoDetect))) &&
 			\defined('STREAM_CRYPTO_METHOD_TLS_CLIENT') && \MailSo\Base\Utils::FunctionExistsAndEnabled('stream_socket_enable_crypto'));
 	}
 }