diff --git a/app/src/main/java/eu/faircode/email/EmailService.java b/app/src/main/java/eu/faircode/email/EmailService.java
index 969f2f3706..ab19954b03 100644
--- a/app/src/main/java/eu/faircode/email/EmailService.java
+++ b/app/src/main/java/eu/faircode/email/EmailService.java
@@ -882,6 +882,9 @@ public class EmailService implements AutoCloseable {
                 }
 
             // Verizon
+            // https://senders.yahooinc.com/developer/documentation/#imap-modes-limited
+            // https://www.ietf.org/archive/id/draft-melnikov-imap-uidonly-00.html
+            // https://answers.microsoft.com/en-us/outlook_com/forum/all/why-is-an-imap-inbox-only-displaying-10000-items/6d15de5f-9047-4b41-9b58-1d8345bbd002
             if (false && istore.hasCapability("X-UIDONLY") && istore.hasCapability("ENABLE"))
                 try {
                     istore.enable("X-UIDONLY");