:0
* ^Subject:.*[response-email]
| /path/to/your_script

mailbox_command = procmail -a "$EXTENSION"

#!/bin/bash

MyUSER="SET-MYSQL-USER-NAME"
MyPASS="SET-PASSWORD"
MyHOST="localhost"
MyDB="SET-DB"

for mFile in `grep -iR 'WHAT TO FIND???' .`
do
  # here do something with your e-mail z.B:
  mysql -u $MyUSER -h $MyHOST -p$MyPASS MyDB << EOF
      insert into ...
      values ...;
  EOF
done