diff --git a/lib/notification/adapter/smtp.md b/lib/notification/adapter/smtp.md
index b1be0e0..bed04ef 100644
--- a/lib/notification/adapter/smtp.md
+++ b/lib/notification/adapter/smtp.md
@@ -20,3 +20,4 @@ Common SMTP settings:
 - **Gmail** - `smtp.gmail.com`, port 587, secure: false
 - **Outlook** - `smtp.office365.com`, port 587, secure: false
 - **Yahoo** - `smtp.mail.yahoo.com`, port 465, secure: true
+- **Gmx** - `mail.gmx.net`, port 587, secure: true