I must be blind or something, but I can't find where to change the limit on how many PMs can be stored. You'd think that an Administrator's Inbox would not be limited, but it is.

I have Invision Power Board(Trial) v2.0.0 PF 1.

Thanks for any help.

It's in the "Group" control panel.

go to Users and Groups > Manage Groups > {Your Admin Account name} > Edit Group > Global Permission > Max. Number of storable messages?

change it to 0..

0 = unlimited
-1 = disable

Thanks for your help everyone. Much appreciated.