I am reposting this question. I initially posted it yesterday but I desperately need an answer.

Is it possible to do any of the following in the message center module in DNN 6.2:

1) Prevent certain security roles from sending messages (or just prevent everyone but the host/admin from sending messages). 

2) Get rid of the searching for users drop down display of usernames that comes up when a user begins to type a username in the Send To box after clicking Compose New Message.

I want messaging capabilities on my site, but only for admins sending messages to specific security roles or users. I do not want users to be able to send messages to other ones. I can live with that problem if I can get rid of this drop down menu because no users will have any clue about the user names of other users on my site so it would be very difficult for them to send messages to other users without this drop down display.

OK. I currently do not have any social groups on my site because I don't think I will need them. I could be wrong though.

I think the autocomplete feature is a deal-breaker for me though because for security purposes I cannot have any users having any clue about the usernames of other users on the site even if they cannot message them since they may not be part of the same social group. From above, you seem to be implying that regardless of what social groups I have on my site, the autocomplete feature will allow any user to possibly find out the username of another user on my site simply by luckily guessing the beginning of their username. Is this the case?

Also, I should ask: is it possible to make this core edit that you speak of?

OK, I think it may be populated with all users though because my site has no social groups, so no user has friends and no user has followers, but when I create a few test accounts, all of the users that match an autocomplete query will show up.

I will take a look at the files that you mentioned above though. Thank you very much for that.