diff --git a/docs/content/a-mail-server's-101.md b/docs/content/a-mail-server's-101.md
index 907e8c4d..030f3f8a 100644
--- a/docs/content/a-mail-server's-101.md
+++ b/docs/content/a-mail-server's-101.md
@@ -72,7 +72,7 @@ Three main purposes exist when it comes to exchanging emails:
 - _Transfer_ (aka. _Relay_): for a MTA, the act of sending actual email data over the network, toward another MTA (server) closer to the final destination (where a MTA will forward data to a MDA).
 - _Retrieval_: for a MUA (client), the act of fetching actual email data over the network, from a MDA.
 
-Postfix handles Submission (and might handle Relay), whereas Dovecot handles Retrieval. They both need to be accessible by MUAs in order to act as servers, therefore they expose public endpoints on specific TCP ports. Those endpoints _may_ be secured, using an encryption scheme.
+Postfix handles Submission (and might handle Relay), whereas Dovecot handles Retrieval. They both need to be accessible by MUAs in order to act as servers, therefore they expose public endpoints on specific TCP ports. Those endpoints _may_ be secured, using an encryption scheme and TLS certificates.
 
 When it comes to the specifics of email exchange, we have to look at protocols and ports enabled to support all the identified purposes. There are several valid options and they've been evolving overtime.