gregster1
The Intuity Audix R4.3 was purchased with right-to-use disk space, not mailboxes. You should be able to enter "change system limits" and grow the number of subscribers to just about anything (we have some that are set for 15,000. However, the RTU disk space may not allow you to just support that amount of subscribers because you only have access to a limited part of the overall disk space.
You should be able to go to CUSTOMER/SERVICE ADMINISTRATION, then DIAGNOSTICS, then SYSTEM EVALUATION for all your answers. The report will detail what you have in terms of purchased features and available capacity.
WARNING! If you're planning to upgrade to Intuity 5.1 (and I recommend it), you could get screwed out of all the spare disk space if you're not carefull. RTU is based on mailboxes not disk space in the R5.1 platforms. The Avaya upgrade process does not take into account the RTU disk space, only in-use mailboxes. After the upgrade you could be forced to BUY additional mailboxes immediately. The solution: Prior to having Avaya configure your upgrade you should build "dummy" mailboxes to account for paid for growth. You should shot for 2100 in a MAP5, 3000 in a MAP40, and upwards of 6000 in a MAP100. It's a little work, but you'll save $25,000-80,000 depending on how much growth you want in your system.
Good luck, WHCARon