Each user has a set limit on the number of messages their PM mailboxes can store. If you reach your limit, you won't be able to receive anymore messages, except from the forum Administrators.

The only way to remedy this is to clear your PM mailbozes. However, just clearing your inbox won't always help (at least in the long term). The messages in your SENT box also count towards your quota, so be sure to remove any files you don't REALLY need.

If you have any problems with the above, or require more information, please post below.