Zimbra Migration: No Connection Error

Check firewall and security settings blocking the migration connection.

Last updated: 2025-01-15 Troubleshooting

Error Message

Zimbra Migration Error

Fatal error during migration process: No connection could be made because the target machine actively refused it [ip-address]:[port]

This error occurs when the migration tool cannot establish a connection to the Zimbra server.

Connection Blocked

🖥️
Cloudiway
Connection request
🔥
Firewall
Blocking traffic
Zimbra Server
Refused

Root Cause

Security Measures Blocking Connection

The Zimbra server is rejecting the connection attempt. This typically occurs due to security measures like firewalls, server restrictions, or IP-based access controls blocking the migration tool's connection.

Common Blockers

  • • Network firewall blocking incoming connections
  • • Zimbra server firewall rules
  • • IP whitelist not including Cloudiway servers
  • • Port not open or listening
  • • Network routing issues

Solution

Remove Security Restrictions

1

Check Firewall Rules

Verify that your network and server firewalls allow inbound connections on the required IMAP ports (143 or 993).

2

Whitelist Cloudiway IPs

If using IP whitelisting, add Cloudiway's migration server IP addresses to your allowed list.

3

Verify Server Accessibility

Test connectivity from an external location to ensure the Zimbra server is reachable on the internet.

4

Restart Migration

After removing the restrictions, restart the migration process.

Contact Support for IP List

Contact Cloudiway support to obtain the current list of IP addresses that need to be whitelisted for your migration.

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