diff --git a/app/src/dummy/java/eu/faircode/email/SSLHelper.java b/app/src/dummy/java/eu/faircode/email/SSLHelper.java
index b8afee0a4a..b53f5f779d 100644
--- a/app/src/dummy/java/eu/faircode/email/SSLHelper.java
+++ b/app/src/dummy/java/eu/faircode/email/SSLHelper.java
@@ -10,6 +10,7 @@ public class SSLHelper {
                                             boolean secure, boolean cert_strict,
                                             String trustedFingerprint,
                                             ITrust intf) {
+        // https://support.google.com/faqs/answer/6346016
         return null;
     }
 
diff --git a/app/src/main/java/eu/faircode/email/ConnectionHelper.java b/app/src/main/java/eu/faircode/email/ConnectionHelper.java
index 02c6141952..262cab7f2f 100644
--- a/app/src/main/java/eu/faircode/email/ConnectionHelper.java
+++ b/app/src/main/java/eu/faircode/email/ConnectionHelper.java
@@ -720,6 +720,7 @@ public class ConnectionHelper {
     }
 
     static HttpURLConnection openConnectionUnsafe(Context context, URL url, int ctimeout, int rtimeout) throws IOException {
+        // https://support.google.com/faqs/answer/7188426
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         boolean open_safe = prefs.getBoolean("open_safe", false);