Dear ResourceXpress Customer,

There have been several updates from Microsoft regarding the retirement of Basic Authentication in their 365 services.

The latest update from Microsoft can be viewed here. Currently, the planned date of retirement is Oct 1st 2022. Microsoft have also advised that they may temporarily disable Basic Authentication for random tenants as per the below quote.

“IMPORTANT: Sometime in second quarter of 2022 we will selectively pick tenants and disable Basic Auth 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.”

Although this quote advises this will happen in the second quarter of 2022, here at ResourceXpress we have seen a trend in support tickets that suggest this random disabling of Basic Auth is already underway. Several customers have reported that, for a period of 24-48 hours, they have observed the below error message in ResourceXpress.

RXDS-SVC1000 : Service Error:The underlying connection was closed: An unexpected error occured on a send.

The below error has also been observed during these periods.

RXDS-SVC1000: Service Error: The request failed with HTTP status 401: Unauthorised

This error message historically pointed to a mismatch of TLS protocols between ResourceXpress and Exchange however, it also seems to be showing for tenants where Basic Authentication has been disabled. In all recent cases this error has disappeared after 24-48 hours.

Next Steps

To ensure your ResourceXpress application continues to operate when integrated to an Exchange Online environment you should configure Modern Authentication immediately. As well as configuring Modern Authentication, we strongly recommend the use of Graph API instead of Exchange Web Services (EWS).

The minimum RX version required for Modern Authentication support is 4.9j, released in November 2019.

The minimum RX version required for Graph API support is 2021.3, released in April 2021. The recommended version for full Graph support is 2021.6 (September 2021).

Please review our original announcement for further information on checking which authentication method is in use.

Other Useful Links

O365 Modern Auth Configuration (EWS)

O365 Modern Auth Configuration (Graph API)

ResourceXpress V4 to V5/202x.x Upgrade Considerations