Recently, users have been reporting intermittent issues with sending emails (GP SMTP Email Failure). Affected areas include emails sent from GP’s workflow engine or standard emails for customer statements. These have been failing with SMTP (Simple Mail Transfer Protocol) authentication errors.
Will I Be Affected?
- If you use Microsoft’s Exchange Online (part of the Microsoft 365 suite) as the email service and
- You are using Dynamics GP version 18.2 or older, then you will be affected
Why Am I Not Affected?
- You do not use Microsoft’s Exchange Online
- You are on a version of Dynamics GP 18.3 and higher
- You do not use the Web Client, Web Services, Emailing, Workflow email notifications on Dynamics GP. You also do not actively use Dynamics GP’s Excel Refreshable Reports
What Change is Causing This?
- Microsoft’s policies to improve authentication security for the Exchange Online service has resulted in this. Issues will exist with software and devices that do not support the more modern authentication methods and protocols
- Dynamics GP versions 18.2 and older use TLS 1.0 for communication
Supporting News from Microsoft
February 2021 (Read More):
- Microsoft made announcements about their plans to turn off Basic Authentication methods in Exchange Online
September 2021 (Read More):
- Microsoft announced that “effective October 1, 2022, we will begin to permanently disable Basic Auth in all tenants, regardless of usage, with the exception of SMTP Auth.”
- Additionally, in 2022, they will roll out the changes necessary to support the above effort, and will begin disabling Basic Auth for some customers with usage on a short-term and temporary basis
- During this time all clients and apps that use Basic Auth in the selected tenants will be affected, and they will be unable to connect. Any client or app using Modern Auth will not be affected. Users can switch to other clients (for example, use Outlook on the Web instead of an older Outlook client that does not support Modern Auth) while they upgrade or reconfigure their client apps
October 2021 (Read More):
- Exchange Online removed support for TLS 1.0 & TLS 1.1 and Basic Auth on the SMTP endpoint smtp.office365.com. Microsoft advised that if you still need to use the older TLS versions, you can enable legacy TLS mode on your Exchange Online tenant as a temporary workaround and then use the smtp-legacy.office365.com endpoint instead
- We are unable to advise how long the temporary workaround would last nor if it would work at all for your particular scenario