Is there a limit to how many messages per inbox it will keep on the pre? I come from using an ipod touch where it would only keep the last 50 messages. When it synced new mail it would remove old messages to keep the count at 50. I thought this was what the 'show email' option in preferences, yet that it would work on the age of mail and not the count. I have mine set to 7 days yet it keeps mail older than 7 days synced. Thoughts?