This message was posted on behalf of Intel Corporation
Thank you for contacting Intel Technical Support,
We received your inquiry and I understand that you are looking for processors information/comparability. Please accept our apologies for any inconvenience this may be causing. We will be more than happy looking for a solution.
Upon rewiring the information you provided. We want to share with you that the Intel® Xeon® Processor E3-1275 v5 is still on lunched status you can review that in this link https://ark.intel.com/compare/88177,97478, also on that same link you will see a comparison between the Intel® Xeon® Processor E3-1275 v5 and the Intel® Xeon® Processor E3 v6.
For information on distributors these links can help you locate them:
In addition is important to take into consideration if the HP ProLiant ML10 is comparable with Intel® Xeon® Processor E3 v6, we advise to contact the manufacturer to get that information
I would add that you should also check with HP to ensure that the BIOS has support for the newer processor variants.