Zimbra Error Queue report unavailable – mail system is down

Logged into the server and then checked the mail log and it continuously generating “Queue report unavailable – mail system is down”.

I have run the following to find out the root cause.

1. Run the “df -hT” command to check the Hard disk space.
2. “top” command to check the memory usage of the system.
3. Then run the /etc/init.d/zimbra status, it shows all the services running. No issues at all.
4. Checked the “netstat -ant | grep 25” zimbra listening on the port as well.

So far other than the maillog error it does not give any error message. As usual, google the error message and found solution for the issue.

It's issue with the postfix master.pid file. To rectify it, need to remove the master.pid file and restart zimbra service again. Issue below commands.

1. find / -name master.pid
2. cd /opt/zimbra/data/postfix/spool/pid/
3. mv master.pid master.pidori
4. then /etc/init.d/zimbra restart

This will solve the issue.

Reference : http://guru4hp.blogspot.com/2014/09/zimbra-reports-error-queue-report.html

Suddenly Proxy stop answering to Users TCP/MISS 503 error

Error : Users are experiencing web site surfing issues with the proxy. They can not surf any website and in the access.log file all the requests have logged as TCP/MISS 503 error message.

To rectify the issue try with the below workarounds.

1. Clear the squid cache folder located in /var/spool/squid
2. Rearrange the ACLs with new configuration.

But issue remains. Then I have given full access to all the users to confirm the issue. Once users get the full access they able to access the Internet. With that it's confirmed that issue is with the proxy.

While monitoring the access.log it found that users were able to access the sites with the IP address. Then able to figure out the root cause is that proxy failed to resolve Hostname to IP address.

Solution :

checked the squid configuration file. /etc/squid/squid.conf

It has three name servers configured.

I have changed the name servers to google DNS, then restart the proxy server. Finally it fixed and users able to surf Internet through proxy.