limit changed to 20MB.
size limit was too high. reset to 10MB. [root@mail ~]# su - zimbra [zimbra@mail ~]$ postconf message_size_limit message_size_limit = 78643200 [zimbra@mail ~]$ zmprov modifyConfig zimbraMtaMaxMessageSize 10240000 [zimbra@mail ~]$ postfix reload /postfix-script: refreshing the Postfix mail system [zimbra@mail ~]$ postconf message_size_limit message_size_limit = 10240000
mail server is accepting emails larger than 10MB. this results in delays and retries.