Trying to put together this:
Trigger Google Apps Script by email
with this:
Custom Incoming Mail Domain With Google App Engine
So that ultimately we can process emails to a scalable inbox @ourgoogleappsdomain.com. Google apps accounts slap a limit of 10,000 a day, which way doesn't work for us. Services that seem to supply this feature, just not at the scale we need, include:
So yes - trying to see what we can do to avoid rolling our own mail server here.