Last night, while conducting a routine security/settings audit, I realized that the gradually-increasing PM limits are a little strange. Only increasing by 10 per step is kinda stingy, and barely noticeable unless your inbox is full. So, I've upped the limits for all groups above Red level to give more generous PM counts, and reward our most active/long-term members with much more comfortable inbox sizes. Full details of the PM inbox size limits are here:
http://www.furryteens.org/forum/index.php?topic=3168.0