Large Email Account Size Import Issue "ERROR: service.FAILURE (system failure: POST failed, status=504 504)"

Hello everyone,

I'm encountering the "ERROR: service.FAILURE (system failure: POST failed, status=504 504)" issue when importing emails from my old Zimbra server. This issue only occurs on one email account with a fairly large inbox. The total inbox count is "Total for user@mydomain.com = 52377." I've set zmlocalconfig -e socket_so_timeout to 3000000 to 99999999, etc., but none of these have resolved the issue.

I'm getting frustrated. Is there a free solution I can use?

Thank you.