Updated FAQ

FAQ.md

@@ -1472,6 +1472,11 @@ If the connection is unstable, this can result in extra data usage.
 In this case, it is a good idea to decrease the number of days to synchronize messages for to a minimum (see the previous question)
 or to switch to periodically synchronizing of messages (receive settings).
 
+To reduce data usage, you could change these advanced receive settings:
+
+* Check if old messages were removed from the server: disable
+* Synchronize (shared) folder list: disable
+
 By default FairEmail does not download message texts and attachments larger than 256 KiB when there is a metered (mobile or paid Wi-Fi) internet connection.
 You can change this in the connection settings.