After reading this question Reasons NOT to use email for system integrationI want to ask the opposite question.What is email ingestion?When it is OK to use it for process or system integration?
What is email ingestion and are there modern uses for that technology?
email;email ingestion
Email ingestion is reading emails from an inbox and processing them.It is used to achieve a degree of automation between two companies, where neither company wants to go through the time and expense of publishing and consuming a first-class API like a REST service.It is suitable:When the communication is not critical, or can be retried (since email is not guaranteed delivery).When the communication is of a document-centric nature.When the chunk of data being sent is relatively large and the number of messages over time is relatively small.There's lots of things you can do with emails.  You can put a chunk of JSON or XML in them for a machine to uptake.  You can put a GUID in the email address that steers the email to a particular record in a database.You can extract the attachments and put them in a document system, etc.A simple example of such intake is used by Trello.  You can send an email to Trello with a specifically-crafted email address, and it will create a new Trello card in the Trello Board you specify, containing the email body as the content of the Trello card.