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Blacklist

When MailBridge attempts to retrieve messages from a connected mail server, individual messages may cause persistent errors, for example due to corruption, unsupported formats, or temporary server inconsistencies.
To prevent repeated failures on subsequent polling cycles, such messages are added to a local blacklist.

Once blacklisted, these messages are skipped in future retrieval attempts until the blacklist is cleared or the MailBridge cache is reset.

Configuration

The blacklist behavior can be controlled through the following configuration property in the instance configuration:

PropertyDefaultDescription
mailBridgeBlacklistEnabledtrueEnables or disables the blacklist mechanism globally for all MailBridge instances within the system.

When set to false, messages that previously caused retrieval errors will continue to be processed in each polling cycle. This can increase load and error log volume but may be useful for debugging purposes or when the root cause has already been fixed externally.

warning

Disabling the blacklist applies system-wide and affects all MailBridge instances. It should only be used temporarily for diagnostic purposes.

Lifecycle and Reset

The blacklist is maintained in memory by the MailBridge process and is cleared automatically in the following situations:

  • When the MailBridge service is restarted.
  • When the server executes a ClearCache operation.

If necessary, the blacklist can also be manually reset using administrative tools that trigger a cache clear on the MailBridge component.

info

A cache reset also clears other transient data. It should be executed with care, especially in production environments.

  • Keep mailBridgeBlacklistEnabled enabled in production environments.
  • Use ClearCache when known issues on the mail server side have been resolved.
  • Disable the blacklist only in exceptional cases for troubleshooting or controlled reprocessing.