Sounds like you could set up the file (dataset) for CA-7 dataset triggering and not need to even need the emails anymore. There should be information about dataset triggering in the manuals but it works something like this:
The vendor/company makes updates to a file on the PC side and then FTP's it to the mainframe, creating an unique dataset name. This unique dataset is defined and linked in the SASSXDSN load member, which is specified in your CA7SFxxx parm member. It also needs to be defined in CA-7 as a trigger. CA-7 will detect the dataset when it is created and auto triggers job or jobs to run. Final step in your processing should be to delete the dataset once all processing is completed successfully, so that it's ready to start the process all over when the dataset arrives the next day.
z/OS Mainframe Systems Programmer
Office of Information Technology (OIT), Development, Security and Operations
Infrastructure Operations (AITC Station 200) (005OPA31E)