10291 Recon and testing

Recon and testing notes take whilst looking into fix for Issue 10291. Contains notes on the OS, and postfix configuration of the machine (prox34) listed in the issue. It also contains some notes on the default posfix configs applied on a fresh install. Contains notes on the steps taken to reproduce the issue, and the proposed fix.

error-repro: Contains all the files used for reporducing the issue, along with a sample of the logs generated as part of the testing.

error-fix: Contains all the files used for testing the proposed fix.