diff --git a/README.md b/README.md
index 6e04255..7b0565b 100644
--- a/README.md
+++ b/README.md
@@ -144,6 +144,7 @@ Image: anonaddy/anonaddy:latest
 
 * `MAIL_FROM_NAME`: From name (default `AnonAddy`)
 * `MAIL_FROM_ADDRESS`: From email address (default `anonaddy@${ANONADDY_DOMAIN}`)
+* `MAIL_ENCRYPTION`: Encryption protocol to send e-mail messages (default `null`)
 
 ### Postfix
 
diff --git a/rootfs/etc/cont-init.d/03-config.sh b/rootfs/etc/cont-init.d/03-config.sh
index 323a838..6fb5863 100644
--- a/rootfs/etc/cont-init.d/03-config.sh
+++ b/rootfs/etc/cont-init.d/03-config.sh
@@ -70,6 +70,7 @@ ANONADDY_ADDITIONAL_USERNAME_LIMIT=${ANONADDY_ADDITIONAL_USERNAME_LIMIT:-3}
 
 MAIL_FROM_NAME=${MAIL_FROM_NAME:-AnonAddy}
 MAIL_FROM_ADDRESS=${MAIL_FROM_ADDRESS:-anonaddy@${ANONADDY_DOMAIN}}
+MAIL_ENCRYPTION=${MAIL_ENCRYPTION:-null}
 
 POSTFIX_DEBUG=${POSTFIX_DEBUG:-false}
 POSTFIX_SMTPD_TLS=${POSTFIX_SMTPD_TLS:-false}
@@ -208,6 +209,7 @@ MAIL_FROM_ADDRESS=${MAIL_FROM_ADDRESS}
 MAIL_DRIVER=smtp
 MAIL_HOST=localhost
 MAIL_PORT=25
+MAIL_ENCRYPTION=${MAIL_ENCRYPTION}
 
 PUSHER_APP_ID=${PUSHER_APP_ID}
 PUSHER_APP_KEY=${PUSHER_APP_KEY}