Office 365 Won’t Block Old Clients But End in Sight for Office 2013

Updating Office applications

A Reminder About the Demise of Office 2013

Microsoft originally published Office 365 notification MC190854 in September 2019 to advise tenants that support will end for Office 2013 client connections to Office 365 applications on October 13, 2020. They’ve just republished the notification as MC218020 to remind everyone that the date is approaching and it’s time to act. The original end-of-support announcement was in April 2017, so no one should be surprised at this point. But some will be.

Microsoft has softened their line a little since 2017. Then they said that “it will be required to have Office 365 ProPlus (now Microsoft 365 apps for enterprise) or Office perpetual in mainstream support to connect to Office 365 services.” Now they say that they’ll will not take “any active measures to block older Office clients, such as Office 2013 and Office 2010, from connecting to Office 365 services.” The bite is in the comment that “legacy clients…may experience performance and reliability issues.”

We Told You Things Will Break

In other words, after October 13, 2020, you can continue using Outlook 2013 to connect to Exchange Online, but you’re on your own and shouldn’t be surprised if some feature stops working or the client connects intermittently or not at all. In addition, the deprecation of basic authentication for many connection protocols for Exchange Online means that all clients must use modern authentication. Finally, without security updates for older clients, a higher risk exists that an attack will succeed through a weakness fixed in a current version.

Microsoft’s update says, “Support for Office 2016 and Office 2019 connections to Office 365 cloud services will continue until October 2023.”  This is the end of mainstream support for Office 2019 and it’s curious that they use the same date for both versions. Perhaps this is to emphasize to Office 365 tenants that the days of perpetual licensing for the Office desktop applications are ending. Microsoft wants customers to transition to Microsoft 365 apps for enterprise, which use the click to run technology to upload clients.

Click to Run Glitches

Click to run normally works very well, but examples do exist when things go wrong, such as the botched update of July 14 which stopped Outlook connecting to Exchange Online and caused some tenants to rollback to a previous build by running the OfficeC2RClient program (see note below). The update to version 2007 was fine on my PC, probably because I had waited to apply it and was covered by the patch Microsoft issued. Overall, my experience is that the way Microsoft rolls out click to run updates is easy for users to deal with (if they’re told what to do when an update is offered as in Figure 1).

Figure 1: It’s time to update Microsoft 365 apps for enterprise (click to run)

Choice Between Click to Run and Browser Apps

Faced with the decision what to do about outdated Office software, it’s hard not to recommend using the Microsoft 365 apps for enterprise, even if it costs more to upgrade users to Office 365 E3 licenses (the plan which includes these apps). On the other hand, a strong case exists that given the way people work today, it’s time to move away from desktop apps and use browser and mobile apps instead. OWA is now a fine client that’s more than an adequate replacement for Outlook desktop unless you absolutely need some Outlook-specific functionality that OWA can’t deliver.


Just in case you need this information, to revert to a previous version of Office Click to Run, open a command (CMD) window, change to the directory where the program is located, and run the program, stating which version you want to use:

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