Answer from JavierM-Xerox:
One caveat - it's been over 7 months since I used the current version of FFCore so some of this stuff may not be available until a month or so when the next version comes out.
This should be a pretty simple check to automate if the customer email and the required dimensions are passed to FFCore.
For the dimensions: Not sure how you are submitting jobs to FFCore, but we would need to define numeric variables with the width and height Those are defined in the MAX Setup tab within the hot folder setup
Once they are defined, you can use them in the preflight check
you can then route the job based on the preflight result and use the external component to send out an email to the customer
Blat (and pretty much every other CLI email client) supports HTML emails so you can setup a customized template and inject whatever variables you want into it before emailing.
When a customer sends us the pdf file for lets say business cards which are supposed to be 9*5cm, but he sends a file with business cards 5*5cm - Ideally we would like him to get an email about it to double check and send it again to us without us having to go through every single file manually, open it, try to find out what happened and then notify the customer. Can this system be somehow automated? Previously (in the older version of the program), thanks to what the printer found out during the job, the customer got an automated notification on their email.