Recently, one of my customers reached out to me stating they were having trouble delivering emails due to SPF failures. While it’s not uncommon for SPF checks to fail (you don’t want to know how many organizations struggle implementing SPF records correctly!), I was a little surprised. After all, the customer had successfully implemented SPF records for quite some time now, and rarely ran into issues with it. In fact, they are quite the example for some of my other customers as their SPF policy is set to a hard failure. Needless to say: a lot of effort went into it, to ensure their SPF records were correct/up-to-date/etc. However, that's not the point here. What follows is an overview of what we've discovered during our troubleshooting. To me, it revealed some interesting routing logic in EOP –some of which is barely (not) documented.
ENow Software's Exchange blog built by Microsoft MVPs for IT/Sys Admins.
Yesterday, Microsoft issued its monthly security bulletin. This time around, the bulletin also includes a fix for a vulnerability that affects only Exchange 2013 environments.
To recap – the previous parts (should you wish to read them, refresh or catch up) can be found below:
We established our domain design, covered how to provision the Domain Controller for the LAB in Hyper-V and then how to install Windows Server 2012 on the Domain Controller.
We went through the process of installing Active Directory Domain Services on the LAB domain controller using PowerShell.