The On Premise Engine has a variety of logging options to enable detecting errors and diagnosing issues.
Logs are configured via a log4net configuration file that lives in the directory with the EmailFetcher. There is a template file distributed with the deployable package named log4net-template.config which you'll rename to log4net.config.
What gets logged?
Enough information will be logged to diagnose issues. When full logging is enabled the following details are logged.
Severity levels of logs
Mailbox (email address) being processed
Environment settings (Processor count, non-secret configuration options)
ID of objects processed
Delta tokens used for keeping track of where it left off
Email Folder an email came from - Useful when customers have questions about whether a folder was seen or not.
Date of emails or meetings (possibly)
What isn't logged
The On Premise Engine will not log any details for the contents of emails or meetings including the body content or the subject lines, email signatures or raw contact details.
Where logs are sent
Where logs are sent to can be configured in the log4net.config file. The default implementation will send the logs to the Console, to a file on the local machine and to AWS.
The customer can turn off the AWS logging by modifying this log4net.config file.
AWS logging will only work if the server can talk to the internet.
It is possible to limit what logs get sent to AWS. For example, the log4net config files supports only logging ERROR level or WARN level and above to AWS. This will make it harder to debug certain issues but is better than nothing.