Steps to reproduce:

1. We have configured SAML authentication with Microsoft Azure according  11 SAML setup with Microsoft Azure AD (zabbix.com)
2. see configuration.png
3. When I try to login I receive an error message that the atribute user_email is missing in user attributes
4. see error_message.png
5. I've captured the response from Azure with the SAML Message Decoder and I see the atribute there:
         <Attribute Name="user_mail">
           <AttributeValue>[email protected]</AttributeValue>
         </Attribute>
6. see SAML_response.txt
7. When I try to configure another attribute in Zabbix, which is in the SAML response the message is similar only the name of the atribute in the message is different.

Result:
The user is not logged in and created.
Expected:
Is it a bug or we have something wrong in the configuration?