diff --git a/README.md b/README.md
index 9a3f0ee8..630ce259 100644
--- a/README.md
+++ b/README.md
@@ -29,10 +29,10 @@ It is a one-click email appliance. There are no user-configurable setup options.
 The components installed are:
 
 * SMTP ([postfix](http://www.postfix.org/)), IMAP ([dovecot](http://dovecot.org/)), CardDAV/CalDAV ([Nextcloud](https://nextcloud.com/)), and Exchange ActiveSync ([z-push](http://z-push.org/)) servers
-* Webmail ([Roundcube](http://roundcube.net/)), mail filter rules (also using dovecot), email client autoconfig settings (served by [nginx](http://nginx.org/))
+* Webmail ([Roundcube](http://roundcube.net/)), mail filter rules (also using dovecot), and email client autoconfig settings (served by [nginx](http://nginx.org/))
 * Spam filtering ([spamassassin](https://spamassassin.apache.org/)) and greylisting ([postgrey](http://postgrey.schweikert.ch/))
 * DNS ([nsd4](https://www.nlnetlabs.nl/projects/nsd/)) with [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework), DKIM ([OpenDKIM](http://www.opendkim.org/)), [DMARC](https://en.wikipedia.org/wiki/DMARC), [DNSSEC](https://en.wikipedia.org/wiki/DNSSEC), [DANE TLSA](https://en.wikipedia.org/wiki/DNS-based_Authentication_of_Named_Entities), [MTA-STS](https://tools.ietf.org/html/rfc8461), and [SSHFP](https://tools.ietf.org/html/rfc4255) policy records automatically set
-* TLS certificates automatically provisioned [Let's Encrypt](https://letsencrypt.org/)
+* HTTPS TLS certificates are automatically provisioned using [Let's Encrypt](https://letsencrypt.org/) (needed for webmail, CardDAV/CalDAV, ActiveSync, MTA-STS policy, etc.).
 * Backups ([duplicity](http://duplicity.nongnu.org/)), firewall ([ufw](https://launchpad.net/ufw)), intrusion protection ([fail2ban](http://www.fail2ban.org/wiki/index.php/Main_Page)), and basic system monitoring ([munin](http://munin-monitoring.org/))
 
 It also includes system management tools: