Mail sender [email protected]

Hi
in function.php there is

add_filter( 'wp_mail_from', 'wpb_sender_email');
function wpb_sender_email( $original_email_address ) {
   return '[email protected]';
}

but all e-mail sended with this plugin activated has header with:

Content-Type: text/html; charset=UTF-8
From: My Company <[email protected]>
Sender: [email protected]

Result
In Microsoft Outlook appear this Sender “[email protected] per conto di My Company <[email protected]>”

I have found
in file: plugins/post-smtp/Postman/Postman-Mail/PostmanDefaultModuleTransport.php
at line: 44
this code: $this->fromEmail = apply_filters( 'wp_mail_from', 'wordpress@' . $sitename );

that override my code in function.php.

Why?