diff --git a/app/src/main/java/eu/faircode/email/Core.java b/app/src/main/java/eu/faircode/email/Core.java
index b8d71dfd87..038880ed2b 100644
--- a/app/src/main/java/eu/faircode/email/Core.java
+++ b/app/src/main/java/eu/faircode/email/Core.java
@@ -140,7 +140,7 @@ class Core {
     private static final int MAX_NOTIFICATION_DISPLAY = 10; // per group
     private static final int MAX_NOTIFICATION_COUNT = 100; // per group
     private static final long SCREEN_ON_DURATION = 3000L; // milliseconds
-    private static final int SYNC_CHUNCK_SIZE = 200;
+    private static final int SYNC_CHUNCK_SIZE = 100;
     private static final int SYNC_BATCH_SIZE = 20;
     private static final int DOWNLOAD_BATCH_SIZE = 20;
     private static final int SYNC_YIELD_COUNT = 100;
@@ -3119,6 +3119,7 @@ class Core {
                                 if (first > 0)
                                     ranges.add(new Pair<>(first, last < 0 ? first : last));
 
+                                // https://datatracker.ietf.org/doc/html/rfc2683#section-3.2.1.5
                                 List<List<Pair<Long, Long>>> chunks = Helper.chunkList(ranges, SYNC_CHUNCK_SIZE);
 
                                 Log.i(folder.name + " executing uid fetch count=" + uids.size() +