Poll emails using JMAP

n8n does not currently offer a way to retrieve emails from arbritrary providers via a regular node. Unless you're using Gmail or Outlook, you can only use the email trigger to start a workflow when a new email arrives. This currently limits the possible use cases you can cover in your n8n workflows, as you cannot (for example) get an idea of how many unread messages there are in an inbox, or search for specific messages when an event occurs. But fear not, there's a new sheriff in town! The JMAP standard allows you to interact with your mailboxes, calendars and contacts through single HTTP requests whenever needed. This n8n workflow demonstrates how to retrieve the total number of unread mess

Help me set up the n8n workflow "Poll emails using JMAP" (https://n8n.io/workflows/2032). It uses: HTTP Request. Import the template JSON into my n8n instance, list every credential I need to create, and walk me through testing it.