Plesk Panel- horde webmail sending attachment as links !!!

Horde sends attachment as:-
1. a link
2. a physical file

If you want the attachment as a link, then you need to change the line in "/usr/share/psa-horde/imp/config/conf.php" file like below:-

$conf['compose']['link_attachments'] = true;

else, on the other hand it should be like:-

$conf['compose']['link_attachments'] = false;