diff --git a/lam/docs/manual-sources/chapter-configuration.xml b/lam/docs/manual-sources/chapter-configuration.xml
index 4e79ebd4..27481c7f 100644
--- a/lam/docs/manual-sources/chapter-configuration.xml
+++ b/lam/docs/manual-sources/chapter-configuration.xml
@@ -247,7 +247,8 @@
       <para>SMTP setup:</para>
 
       <para>Mail server: enter name + port separated by ":". E.g. "server:25"
-      will use "server" on port 25.</para>
+      will use "server" on port 25. Please note that your mail server
+      <emphasis role="bold">must</emphasis> support TLS encryption.</para>
 
       <para>User name: enter the user name if your SMTP server requires
       authentication</para>
diff --git a/lam/help/help.inc b/lam/help/help.inc
index c3faaa3c..5719c896 100644
--- a/lam/help/help.inc
+++ b/lam/help/help.inc
@@ -382,7 +382,7 @@ $helpArray = array (
 				// jobs
 				'800' => array(
 					"Headline" => _('From address'),
-					"Text" => _('This email address will be set as sender address of all mails. If empty the system default (php.ini) will be used.')
+					"Text" => _('This email address will be set as sender address of all mails.')
 				),
 				'801' => array(
 					"Headline" => _('Reply-to address'),
diff --git a/lam/templates/config/confmain.php b/lam/templates/config/confmain.php
index b80d5296..eaabb061 100644
--- a/lam/templates/config/confmain.php
+++ b/lam/templates/config/confmain.php
@@ -22,7 +22,7 @@ use \htmlGroup;
 /*
 
   This code is part of LDAP Account Manager (http://www.ldap-account-manager.org/)
-  Copyright (C) 2003 - 2019  Roland Gruber
+  Copyright (C) 2003 - 2020  Roland Gruber
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -614,6 +614,9 @@ function checkInput() {
 		if (!$conf->setLamProMailFrom($_POST['pwdResetMail_from'])) {
 			$errors[] = array("ERROR", _("From address for password mails is invalid."), htmlspecialchars($_POST['pwdResetMail_from']));
 		}
+		if (!empty($_POST['pwdResetMail_subject']) && empty($_POST['pwdResetMail_from'])) {
+			$errors[] = array("ERROR", _("From address for password mails is invalid."), htmlspecialchars($_POST['pwdResetMail_from']));
+        }
 		if (!$conf->setLamProMailReplyTo($_POST['pwdResetMail_replyTo'])) {
 			$errors[] = array("ERROR", _("Reply-to address for password mails is invalid."), htmlspecialchars($_POST['pwdResetMail_replyTo']));
 		}