diff --git a/doc/settings/smtp.md b/doc/settings/smtp.md
index 622ee2ca3703e7445d14080cc017f9cf6dad4a2a_ZG9jL3NldHRpbmdzL3NtdHAubWQ=..fffe5bc4ec05f64139863551f1bd7e4ec4d3f43e_ZG9jL3NldHRpbmdzL3NtdHAubWQ= 100644
--- a/doc/settings/smtp.md
+++ b/doc/settings/smtp.md
@@ -727,6 +727,21 @@
 gitlab_rails['smtp_openssl_verify_mode'] = 'none'
 ```
 
+### Mailbox.org
+
+```ruby
+gitlab_rails['smtp_enable'] = true
+gitlab_rails['smtp_address'] = "smtp.mailbox.org"
+gitlab_rails['smtp_port'] = 465
+gitlab_rails['smtp_user_name'] = "username@example.com"
+gitlab_rails['smtp_password'] = "password_you_set"
+gitlab_rails['smtp_domain'] = "smtp.mailbox.org"
+gitlab_rails['smtp_authentication'] = "login"
+gitlab_rails['smtp_enable_starttls_auto'] = true
+gitlab_rails['smtp_tls'] = true
+gitlab_rails['smtp_openssl_verify_mode'] = 'none'
+```
+
 ### More examples are welcome
 
 If you have figured out an example configuration yourself please send a Merge