Posfix Increase Attachment size

This is how I changes postfix message size:

In file vi /usr/local/cwpsrv/var/services/roundcube/config/defaults.inc.php value was:
$config['max_message_size'] = '100M';

And in roundcube it will show 75 M as Attachment size

When I changed

$config['max_message_size'] = '500M';

It started showing 375 M as attachemnet size.

Not sure how, probably hard coded, but attachment size in Roundcube will always be 75% of what $config['max_message_size'] is. The rest of 25% is for the rest of the message, like the text.

Remember that there are other settings restricting bigger file sizes, like php.ini of the php that is controlling CWP and Roundcube, the htaccess file that's inside the roundcube folder, and the main.cf settings restricting the total message size.

The Attachment size can be queried with this command:

postconf | grep message_size_limit