I hope Mark or Chris or someone else from AC will weigh-in on these message issues.
When we upgraded to 10.0.2 last year, we reported issues with loss of content in messages. Later, I discovered some problems with the way reminders were appearing in the inbox (out of order; showing up on the wrong dates).
We were anxious for a fix but did not upgrade until we got confirmation that the issues were resolved. Are they? Are people using 10.1.6 without problems?
Dru, reminders (the yellow highlighted messages) should not be in the outbox -rarely, if ever. The only exception would be if you got a reminder, sent it to someone else, and they did not open it yet.
You should not have lots of reminders in your inbox unless you are somehow (accidentally?) creating them.
David, can you explain what you mean in more detail?
