Sets the number of maximum transactions supported by the server. Can increase performance on heavily used systems with many concurrent users. These parameters control the behavior of the server task's thread pool, as well as how the thread pool handles client transactions. These parameters only apply to NRPC communication, and hence only apply to the server task, 'nserver.exe' on W32, 'server' on Unix. These parameters do not affect any other task, such as HTTP, IMAP, Router, etc.