How to use the Salesforce Integration (API Only) User License
The Salesforce Integration User license (https://help.salesforce.com/s/articleView?id=release-notes.rn_api_integration_license.htm&release=242&type=5) released in March of 2023 can be used as Email to Case Premium Context User (http://kb.vicasso.com/?kb=000004837) to process inbound emails. This article describes 1) creating the user, 2) assigning the requisite permission set license, 3) creating and assigning a permission set, and 4) modifications to the user's profile. (Salesforce partners cannot package a permission set with all the permissions needed, so this article describes how to make one.)