This post is just a quick reminder that, as announced in November 2016, Exchange Online will stop supporting RPC over HTTP at the end of October, 2017. If you’re still using RPC over HTTP you’re strongly recommended to update your client to one of the currently supported versions of Outlook (which at the moment of writing is 2010, 2013 or 2016 ).
If you’re still using Outlook 2010, please also ensure that you installed the following updates
- KB2687521, download Microsoft Office 2010 Service Pack 2 from https://support.microsoft.com/en-us/help/2687521/list-of-all-office-2010-sp2-packages
- KB3085604, October 2015 PU, getit from https://support.microsoft.com/en-us/help/3085604/october-13-2015-update-for-outlook-2010-kb3085604 – this is the current official minimum required update to connect to Exchange Online when using Outlook 2010
If you did not already install that, you should rather use October 2017 PU KB4011196, which you can retrieve from https://support.microsoft.com/en-us/help/4011196/descriptionofthesecurityupdateforoutlook2010october10-2017 - please also install the update August 2016 PU for Outlook 2010 Junk Email Filter, KB3115475, which you can download from https://support.microsoft.com/en-us/help/3115475/august-2–2016–update-for-outlook-2010-junk-email-filter-kb3115475
If required, please find the original announcement on https://support.microsoft.com/en-us/help/3201590/rpc-over-http-reaches-end-of-support-in-office-365-on-october-31-2017