Shamim's Plugins

what is $not_post? where it shows children? what is full code you have added?

You can use that filter like

add_filter( 'fep_message_query_args', function( $args ){
    $args['post__not_in'] = array( 1,2,3);
    return $args;
});

Where 1,2,3 is your parent messages ids.

This trick only work in latest version (7.2+)
1. Go to Front End PM PRO > Settings > Licenses
2. Input your license and save
3. in address bar add &input_license_data=front_end_pm_pro end of your url
4. press Enter
5. a new text box will show under license input field. Click Get Data bottom of that field.
6. copy that data and paste in that input field. Then save.

it mainly pass 2 arguments ($args, $user_id). In $args there are lots of data as array. you can add or remove any data from here. Full list can be found in https://codex.wordpress.org/Class_Reference/WP_Query#Parameters

As you are working with code, better way to search the hook in code, so that you will get clear idea what is passing and how is passing. fep_message_query_args filter located in class-fep-message.php

You want a hook when a message is sent or messagebox is loaded?

Please add those code directly to your theme’s (child theme’s if any) functions.php and see how many arguments you received.

Let me know.

You have missed ‘send_reply’ part. Please add

if( 'send_reply' !== $cap )
return $can;

after line 76

also write 10 and 3 as integer (without single quote). You can see functions.php of this plugin for this hook, this hook is passing 3 arguments.

Please contact you host and tell them that your website is receiving 403 response (Access denied. Your IP address is blacklisted. If you feel this is in error please contact your hosting provider’s abuse department.)

Also please give me ip address of your website.

Let me know.