diff --git a/en_US/howto/additional.smtp.port.md b/en_US/howto/additional.smtp.port.md
index 637eef7f..0a005d69 100644
--- a/en_US/howto/additional.smtp.port.md
+++ b/en_US/howto/additional.smtp.port.md
@@ -29,6 +29,7 @@ in `/etc/postfix/master.cf` (on Linux/OpenBSD) or
 
 * `2525` is the new port number for smtp service, you're free to change it to
   your favourite port number.
+* `smtpd_tls_security_level=may` allows both secure (TLS) and insecure connections.
 * Restriction rule `permit_mynetworks` will allow clients listed in Postfix
   parameter `mynetworks` to send email __WITHOUT__ smtp auth.
 
diff --git a/html/additional.smtp.port.html b/html/additional.smtp.port.html
index 61ad48cb..518a1fad 100644
--- a/html/additional.smtp.port.html
+++ b/html/additional.smtp.port.html
@@ -52,6 +52,7 @@ in <code>/etc/postfix/master.cf</code> (on Linux/OpenBSD) or
 <ul>
 <li><code>2525</code> is the new port number for smtp service, you're free to change it to
   your favourite port number.</li>
+<li><code>smtpd_tls_security_level=may</code> allows both secure (TLS) and insecure connections.</li>
 <li>Restriction rule <code>permit_mynetworks</code> will allow clients listed in Postfix
   parameter <code>mynetworks</code> to send email <strong>WITHOUT</strong> smtp auth.</li>
 </ul>