I search hack for sending private messages for all users, or any groups. How to do it?

You don't want to do that, it's inefficient. <img src="/forum/images/graemlins/tongue.gif" alt="" />

Very inefficient since users can turn off notification for PM and if they do not visit often they will never see it. EMAIL ALL USERS in admin panel is best way.

But my serwer hasn't installed email function <img src="/forum/images/graemlins/frown.gif" alt="" />

If you really want to do this, you can see an example of sending a PM to a group in admin/derevokemod.php. Look for "Now inform all other Admins and mods". Refer to function send_message() in ubbt.inc.php for allowable values of the $Group parameter.<br /><br />If you wanted to send to a group other than one of those groups, you would need to tweak the code.<br /><br />The reason I said it was inefficient is because each copy of the PM is stored in the database for every user whom it's sent to.

I tried but without any positive result <img src="/forum/images/graemlins/frown.gif" alt="" /><br />How change change option chagne Email to All fo send Pm to all... (cosedemail.php file << executive command)<br />

Yeah, if you have 1000 members, it's like storing the same "post" in the Database 1000 times. <img src="/forum/images/graemlins/crazy.gif" alt="" /> <br /> <br />The bigger the databases get the slower things eventually get. A couple of "bulk PMs" to a large user base could drastically slow down your forums. <img src="/forum/images/graemlins/wink.gif" alt="" /> <br /> <br />If you want certain groups to see an "announcement", then it's best to make a forum that only that group can see and make an announcement there. <img src="/forum/images/graemlins/smile.gif" alt="" /> <br /> <br />Then you only store the message once.