I've set the max size of attachments by using

zimbraMailContentMaxSize
zimbraFileUploadMaxSize
zimbraMtaMaxMessageSize

and i've restarted zmcontrol

Now i can make messages much size instead of default, but i still can't send it with error: message file too big

Code:
zimbra@MailServer: /opt/zimbra/log> zmprov gacf | grep Size
zimbraFileUploadMaxSize: 44040192
zimbraGalLdapPageSize: 1000
zimbraGalSyncLdapPageSize: 1000
zimbraMailContentMaxSize: 44040192
zimbraMailFileDescriptorBufferSize: 4096
zimbraMailFileDescriptorCacheSize: 1000
zimbraMessageCacheSize: 2000
zimbraMessageIdDedupeCacheSize: 3000
zimbraMtaMaxMessageSize: 44040192
zimbraNotebookFolderCacheSize: 1024
zimbraNotebookPageCacheSize: 10240
zimbraRedoLogRolloverFileSizeKB: 1048576
zimbraRedoLogRolloverHardMaxFileSizeKB: 4194304
zimbraSoapRequestMaxSize: 15360000
zimbra@MailServer: /opt/zimbra/log>