(Not workflow emails)
There has been an increase in the number of situations where emails from Dynamics GP are failing and logging into Exchange from GP is failing. This is especially true for older versions of GP as well as current versions (GP 18.3 and newer) that do not have MFA for GP enabled. To warn us that a greater change is coming, the Exchange team is temporarily deactivating basic authentication.
When authentication fails, you will be prompted to enter your credentials repeatedly. For a long time, basic authentication has been on the verge of being deactivated. That moment is approaching sooner rather than later. The newest mention of this can be seen in the Exchange team's blog below.
Effective October 1, 2022, Basic Authentication will be permanently disabled in all tenants, regardless of usage, with the exception of SMTP Authentication.
“Beginning early 2022, we will selectively pick tenants and disable Basic Authentication for all affected protocols except SMTP AUTH for a period of 12-48 hours. After this time, Basic Auth for these protocols will be re-enabled if the tenant admin has not already re-enabled them using our self-service tools.”
You can re-enable basic authentication using the self-service facility supplied during that 12–48-hour window, or you can wait for it to enable again. However, this will only be until October 2022, when it will be completely disabled. If you haven't already, you can opt-out for a limited time so that basic authentication is not turned off temporarily.
To avoid an interruption of emails it is recommended to upgrade to GP 18.4 and enabling MFA before October 1, 2022.
In addition to the measures listed above, TLS has been a problem in older versions of GP. This can become a problem for older applications as separate systems upgrade their security methods. Anything prior to GP 18.4 is considered an older application in GP. Transport Layer Security (TLS) best practices with the .NET Framework - .NET Framework | Microsoft Docs
If your app targets .NET Framework 4.7 or later versions, the switch defaults to false. This is a safe default. The switch defaults to true if your app runs on .NET Framework 4.7 or later but targets an earlier version. In that scenario, you need set it to false directly.
By setting the switch to "false" we are forcing communication to take place over TLS 1.2 which should fix the communication protocol required to send the emails. This repair will not work on Windows 7 machines or older versions of Server Operating systems.
If you would like more information or to upgrade Dynamics GP, contact Rimrock Corporation and one of our consultants will be happy to help.