problem with file attachment size...

[andekhi]

good day sir, i want to ask how to increase maximum file attachment, i have increase with zmprov and the result like this :

zmprov
prov> gcf zimbraFileUploadMaxSize
zimbraFileUploadMaxSize: 26214400
prov> gcf zimbraMtaMaxMessageSize
zimbraMtaMaxMessageSize: 31457280

my question is.. why when i open webclient zimbra and click add attachment, the notification still like this :
Note: Each attachment size limit is 15 MB
i tried to attach file with 15,5mb size but i get warning like this..

At least one file exceeds the file size limit of 15 MB.

i have restart zmcontrol after i change the configuration..

many thanks before