Getting 404 when testing an OAuth 2.0 connection (Helpdesk Email Integration)

[Andres Pinzon]

Hi, 

NOTE - this issue is not in our Jira, but an on-prem Jira server (v8.12.1) that we manage for one of our clients.

We got a Jira server that is used as a helpdesk and it had been set with email support so customers could create issue by sending an email to an MS outlook account.

Recently we noticed this integration wasn't working and we suspected it's due to the basic authentication no longer supported by MS, so we set out to enable OAuth 2.0

We've gone through the process of setting an Azure App registration (as outlined here https://confluence.atlassian.com/jiracore/setting-up-oauth-2-0-integration-1005784173.html  and here https://community.atlassian.com/t5/Jira-Software-questions/Why-can-t-I-connect-to-Microsoft-with-oAuth2-0-setup/qaq-p/1549086#M110700 )

We believe it's been done correctly and is ready to go, however when we try to test the connection we keep getting a 404. The URL has the following format

https://jira.domain/common/oauth2/v2.0/authorize?scope=https%3A%2F%2Foutlook.office.com%2FIMAP.AccessAsUser.All+https%3A%2F%2Foutlook.office.com%2FPOP.AccessAsUser.All+offline_access&... (rest omitted for brevity)

This error doesn't look like an integration issue with the Azure App, but rather a problem with Jira itself.

[Michael Söderberg]

Found a solution that worked for us: https://confluence.atlassian.com/jirakb/jira-and-iis-as-reverse-proxy-with-reverse-rewrite-host-in-response-headers-option-enabled-fails-for-https-777015738.html

[Michael Söderberg]

We have exactly the same problem (jira 8.11.1).