extend sample config and allow setting encryption

config.sample.php

@@ -5,6 +5,18 @@ $config = [
 
     // Which e-mail-adresse shall the bot use to send e-mails?
     "register_email" => 'register_bot@example.com',
+
+    // which settings should be used to send via SMTP Gateway?
+    "smtp" => [
+        "host" => "localhost",
+        "port" => "25",
+        // use authentication?
+        "user" => "register@example.com",
+        "password" => "SecretEMailPassword",
+        // Use some encryption to SMTP-Server? [ssl, tls] or unset
+        "encryption" => False
+    ],
+
     // Where should the bot post registration requests to?
     "register_room" => '$registerRoomID:example.com',
 

mail_templates.php

@@ -35,14 +35,16 @@ function send_mail($receiver, $subject, $body) {
             $mail->isSMTP();                                  // Set mailer to use SMTP
             $mail->Host = $smtp_conf["host"];                 // Specify main and backup SMTP servers
             $mail->Port = $smtp_conf["port"];                 // TCP port to connect to
-            if (isset($smtp_conf["user"])) {
+            if (!empty($smtp_conf["user"])) {
                 $mail->SMTPAuth = true;                       // Enable SMTP authentication
                 $mail->Username = $smtp_conf["user"];         // SMTP username
-                if (isset($smtp_conf["password"])) {
+                if (!empty($smtp_conf["password"])) {
                     $mail->Password = $smtp_conf["password"]; // SMTP password
                 }
             }
-            $mail->SMTPSecure = 'tls';                        // Enable TLS encryption, `ssl` also accepted
+            if (!empty($smtp_conf["encryption"])) {
+                $mail->SMTPSecure = $smtp_conf["encryption"]; // Enable TLS encryption, `ssl` also accepted
+            }
         } else {
             // fallback to sendmail functionality (as before)
             $mail->isSendmail();