I'm going to assume that you are asking about bebot 0.4 not 0.2 as your earlier questions on the forums were on BeBot 0.4...
Check !settings AutoInv, and make sure the feature is activated.
Players can then turn autoinvite on or off with the !autoinvite command.
Unfortunately, there isn't a way for the admin to turn on autoinvite for the bot's existing members.
If you want to do that, you'll have to update the database...
Run mysql:
mysql -u username -p
Enter your password when prompted...
mysql> UPDATE botname_users SET auto_invite = 1;
mysql> exit
Restart your bot and it will autoinvite current members, usually much to their annoyance.