we are using zimbra 7 opensource
we have the issue that some important mails are not received due to max size limit. I cannot believe that there is no hint in the docs. I can't find any helpfull post for this either. The only entry 'wiki/Configuring_maxmessagesize' doesn't work.
Any hints?

zmprov gacf zimbraMailContentMaxSize
: 50000000
zmprov gcf zimbramtamaxmessagesize
: 50000000
postconf message_size_limit
message_size_limit = 25600000

Thank you