I hope you're all doing well. I've recently encountered a recurring issue when accessing our Zimbra Collaboration Suite (ZCS) server, and I'm seeking some guidance on how to resolve it.
When trying to access our ZCS server, I'm consistently encountering the following error message:
Possible Causes:HTTP ERROR 504
Problem accessing ZCS upstream server. Reason: Cannot connect to the ZCS upstream server. Connection timeout.
- Upstream server is blocked by a firewall.
- Upstream server is failing to send back the response in time.
- Upstream server is down.
Please contact your ZCS administrator to fix the problem.
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Based on the error message, it appears that there are several potential causes for this issue, such as firewall blocking, server response delays, or server downtime.
Request for Assistance:
I'm not the administrator of our ZCS server, so I'm reaching out to this community for suggestions on how to troubleshoot and potentially resolve this issue. If anyone has experienced a similar problem or has expertise in Zimbra Collaboration Suite, I would greatly appreciate your insights and recommendations.
Steps Taken So Far:
I've tried clearing my browser cache and cookies, but the issue persists. It seems to be affecting multiple users within our organization.
I plan to contact our ZCS administrator, but I would like to gather as much information as possible to assist them in diagnosing and fixing the problem.
Any advice, troubleshooting steps, or insights you can provide would be incredibly helpful. Thank you in advance for your assistance!