This Processor consumes email messages via POP3 protocol and sends the content of an email message as content of the Flow File. Content of the incoming email message is written as raw bytes to the content of the outgoing Flow File.
Since different serves may require different Java Mail properties such properties could be provided via dynamic properties. For example, below is a sample configuration for GMail:
Processor's static properties:
Another useful property is mail.debug which allows Java Mail API to print protocol messages to the console helping you to both understand what's going on as well as debug issues.
For the full list of available Java Mail properties please refer to here