diff --git a/docker-compose-dev.yml b/docker-compose-dev.yml
index b62db9d4..a3d5c6a7 100644
--- a/docker-compose-dev.yml
+++ b/docker-compose-dev.yml
@@ -54,6 +54,7 @@ services:
       # - SMTP_USER=
       # - SMTP_PASSWORD=
       # - SMTP_FROM="Demo Demo" <demo@demo.demo>
+      # - SMTP_TLS_REJECT_UNAUTHORIZED=false
 
       # Optional fields: accessToken, events, excludedEvents
       # - |
diff --git a/docker-compose.yml b/docker-compose.yml
index d825cbac..e3a4bfde 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -61,6 +61,7 @@ services:
       # - SMTP_USER=
       # - SMTP_PASSWORD=
       # - SMTP_FROM="Demo Demo" <demo@demo.demo>
+      # - SMTP_TLS_REJECT_UNAUTHORIZED=false
 
       # Optional fields: accessToken, events, excludedEvents
       # - |
diff --git a/server/.env.sample b/server/.env.sample
index 28be92ff..8393b1db 100644
--- a/server/.env.sample
+++ b/server/.env.sample
@@ -53,6 +53,7 @@ SECRET_KEY=notsecretkey
 # SMTP_USER=
 # SMTP_PASSWORD=
 # SMTP_FROM="Demo Demo" <demo@demo.demo>
+# SMTP_TLS_REJECT_UNAUTHORIZED=false
 
 # Optional fields: accessToken, events, excludedEvents
 # WEBHOOKS='[{
diff --git a/server/api/hooks/smtp/index.js b/server/api/hooks/smtp/index.js
index dd9ca8df..64aa8641 100644
--- a/server/api/hooks/smtp/index.js
+++ b/server/api/hooks/smtp/index.js
@@ -33,6 +33,9 @@ module.exports = function defineSmtpHook(sails) {
           user: sails.config.custom.smtpUser,
           pass: sails.config.custom.smtpPassword,
         },
+        tls: {
+          rejectUnauthorized: sails.config.custom.smtpTlsRejectUnauthorized,
+        },
       });
     },
 
diff --git a/server/config/custom.js b/server/config/custom.js
index 44a72a14..c10cf5ed 100644
--- a/server/config/custom.js
+++ b/server/config/custom.js
@@ -76,6 +76,7 @@ module.exports.custom = {
   smtpUser: process.env.SMTP_USER,
   smtpPassword: process.env.SMTP_PASSWORD,
   smtpFrom: process.env.SMTP_FROM,
+  smtpTlsRejectUnauthorized: process.env.SMTP_TLS_REJECT_UNAUTHORIZED !== 'false',
 
   webhooks: JSON.parse(process.env.WEBHOOKS || '[]'), // TODO: validate structure