We have just installed OX on a small set of clients at work, to test it out, before deploying full scale. We've run into a problem where syncing is stopped with a HTTP 504 error (as seen in OXTENDER below), which essentually stops the client from downloading new email, syncing contacts etc. This problem is sometimes solved by restarting the client. Waiting for it to sync seems not a viable option. Any input?

Open Xchange Updater 6.18.10

Open Xchange Groupware Server
Version 6.20.1-Rev5
USM Version Build 4634, USM JSON Build 4634

Open Xchange OXtender AddIn for Microsoft Outlook

---- Sync State ----

Error importing folder contents (SST_FOLDERCONTENTS_IMPORT)

---- Message ----

HTTP 504

---- Location ----

Folder: /Inbox

---- Details ----

An intermediate proxy server timed out while waiting for a response from another proxy or the origin server (HTTP 504, Gateway Time-out).

---- Error Object ----

"code": 2148369668,
"code_hex": "0x800d8504",
"code_description": "unknown USM error",
"state": 16,
"state_description": "SST_FOLDERCONTENTS_IMPORT",
"path": "/Inbox",
"entryid": "00000000752607e200c5d14c8fdbd158001b0d26402a2a40f 36726bbddead543ab2fe2f54468afa6232a2a2301030000",
"uuid": "bb2667f3-eadd-43d5-ab2f-e2f54468afa6"
"func": "/usm-json/syncUpdate",
"folderid": "bb2667f3-eadd-43d5-ab2f-e2f54468afa6",
"syncid": 1330700697588,
"limit": 100,
"sessionid": "027495ba-83a6-4738-8e7e-de9a95f8ed34"