Why do you limit the number of users that can be in a group?
We added this limitation for many reasons, however the number one reason was security. We do not want people abusing our software to send net send messages to thousands of users via a range of IP addresses or such. In our market research we found that companies in need of sending our net send messages would not exceed 5 users; if they did a process would split the users into logical groups of 5 to spread out the time it took to resolve/send messages.
It could take up to 60 seconds to determine if a username/computername/ip address is responding, if not it skips that user and moves on. If half the users were no logged in or the computers were not turned on, then it could take up to 3 minutes to walk through the entire list of 5 users. For an "instant message" solution this is not very instant. This was another reason for the limit of 5 users.
However, if you have a specific need to send messages to more than 5 users, please let us know what that is. We have no problems issuing you a registered version that contains a higher limit on the number of users that the software can send to, we just need to cover ourselves. PLEASE contact us with a use case so we can understand your need, be sure to include the number of users you need to send to. We will respond asap with a solution.