Change the maximum attachment size in HordeBy default, PHP limits uploaded files’ size to 2 MB. This limit applies to all PHP applications including Webmail. Edit the following options in the “/etc/php.ini” file on the Plesk server and set the values to match your needs. For example:
upload_max_filesize = 32M
post_max_size = 32MRestart Apache after the “php.ini” file modification.
Also note that the maximum attached file size can be changed by adjusting the Horde configuration. Find the “attach_size_limit” option in the “/etc/psa-horde/imp/conf.php“:
$conf['compose']['attach_size_limit'] = ’0′;
An “attach_size_limit” value of zero means “no limit.”