We have installed ZCS Open Source edition on debian ( squeeze ) linux. We have a issue regarding the attachment size that is send from the external mail servers ( eg: gmail ). The gmail returns and error " Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 552 552 Too much mail data (state 17)."

The output of the postconf | grep -i size is given below

berkeley_db_create_buffer_size = 16777216
berkeley_db_read_buffer_size = 131072
body_checks_size_limit = 51200
bounce_size_limit = 50000
header_size_limit = 102400
mailbox_size_limit = 0
message_size_limit = 44040192
tcp_windowsize = 0

I am trying to send 6MB attachment.

Please let me know what settings needs to be done.