423 The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account.

When sending an email receive a 423 error with:

The user account which was used to submit this request does not have the right to send mail on behalf of the specified sending account., Cannot submit message

Endpoint / Log: 

API

Causes

Account does not have permission to to send on behalf of the other user, the alias has not been configured by the provider.

If this is a company account please see your company Mail Administrator.

Resolution

GMAIL

Add an alias  

Microsoft

Add an alias 

Resources:

https://docs.microsoft.com/nl-NL/previous-versions/troubleshoot/dynamics/crm/errors-occur-when-sending-on-behalf-of-or-send-as-another-user-via-crm-email-router