Shamim's Plugins

You can use fep_filter_rest_users_args filter hook to change where you want to search (for some examples https://www.shamimsplugins.com/support/search/fep_filter_rest_users_args/). Also you can use fep_filter_user_name to change what name you want to show.

This plugin is highly customizable. You can even use fep_filter_rest_users_response to query and response as you like. This will bypass plugin’s query fully.

It seems PRO version is not installed in your website.
Please download PRO version from https://www.shamimsplugins.com/account and install in your website.

and to send message to author only you can set https://www.shamimsplugins.com/docs/front-end-pm-pro/getting-started-2/only-admin/

Let me know if you have any more questions.

I have investigate your website. There should have 4 db tables related to this plugin where we store message and data for this plugin. But i do not find any table of that. Do you by any chance deleted those tables or taken any action which may have deleted these tables?
Do you have any backup when this was working?

Do you have any staging server for this website?
Can you give me access to your staging website so that i can debug? If yes, please send admin and ftp/sftp credentials using https://www.shamimsplugins.com/sensitive-information/

Are you logged in as admin? By default only admin user can add announcement. If you want to allow any other role you can follow https://www.shamimsplugins.com/support/topic/create-announcements/#post-26559

This plugin does not delete attachments automatically. Do you have any custom code for this plugin?

When sending to multiple recipients we have 2 settings
settings 1 (default): Same message: All users will receive same message and replies will be visible to all users
Settings 2: separate message: All users will receive separate message and replies will not be visible to any other users but sender.

You can change this settings in Front End PM PRO > Settings > Recipients > Multiple Recipients

And For email, sender email is not visible to any users. Your email is sent from your systems email address. You can use any Email/SMTP plugin to change that.

You can use following code

add_filter("fep_get_user_option", function( $value, $option, $default, $userid, $is_default ){
    if( $option == "allow_emails" &&  $userid === 123){
        return false;
    }
    return $value;
}, 10, 5);

You can change user id value to chat you want.