auto respond with parametric attachment upon request

[tas75]

hi there to all,



i have around 500 different pdfs that i want to distribute to the respective 500 salesmen upon request.

The process i want to use, is that each person can send to me an empty mail with subject "sales xxx", where xxx is the 3-digit code each salesman has and then an automatic mail containing the respective attachment (e.g. reportxxx_31012017.pdf) will be sent.

do you know how this can be done?