Hi Sally,
Although it is not straightforward and simple, but it should be possible.
I think there are some tools that may help you
1) FM RSPC_API_CHAIN_START to trigger a process chain
2) Call SAP FM as web service (Ref: http://scn.sap.com/docs/DOC-18411)
Say for example you can:
a)
1) Write ABAP to check email and update the CSV attachment into a Z table (And schedule it as job)
2) Create datasource to read data in the Z table
3) ABAP in step 1 call RSPC_API_CHAIN_START to trigger process chain to load data into DSO
4) In the chain: Load data into PSA with DS create in step 2, DTP from this PSA to DSO
b)
1) With some non-SAP tools, you check email and save the CSV to some location where SAP app server can access
2) Write RFC in SAP and enable it as Web Service, where this RFC will process the CSV and trigger process chain to load etc...
3) Trigger this RFC via web service (which should support by most latest tools around) once you done step 1
Regards
Bill