Upgrading from v0.5.3 to v0.6.0

• In order to support expressions, version 0.6.0 introduces multiple breaking changes in the SMTP server configuration file. It is recommended to download the new SMTP configuration files from the repository, make any necessary changes and replace the old files under INSTALL_DIR/etc/smtp with the new ones.
• If you are using custom subaddressing of catch-all rules, you'll need to replace these rules with expressions. Check out the updated syntax.
• Message queues are now distributed and stored in the backend specified by the storage.data and storage.blob settings. Make sure to flush your SMTP message queue before upgrading to 0.6.0 to avoid losing any outgoing messages pending delivery.
• Replace the binary with the new version.
• Restart the service.