Certain older HL7 Listener products require that the sending application establish a connection and once engaged, keep that connection open indefinitely. As a result, if you are operating in DEMO mode or have a PROFESSIONAL license you can set the 'Static' property when creating your mailbox profiles.

If you have purchased a BASIC license, you may not create static mailbox profiles for the obvious reason that you are only using 1 Router Runtime Engine and if it stays engaged to 1 particular profile indefinitely, it isn't free to service any of your other profiles.

Even when running a Professional license, you may only create 9 static profiles, again for the obvious reason that since the system is only running 10 Router Runtime Engines, you MUST keep at least 1 of them free to service your other 'Dynamic' profiles.