Appwrite Functions on Appwrite Cloud can now execute when an email arrives. Turn on the Email trigger of a function, and an email sent to an address such as support@<FUNCTION_ID>-<PROJECT_ID>.appwrite.email executes it. You can also connect a domain that you own with an MX record and a TXT record.
Your function receives the email as JSON and each attachment as a file in one multipart/form-data request, together with a spam score that it can use to decide what to keep.