The JIRA Server could not be contacted from Mail Handler Configuration Page
Platform Notice: Server, Data Center, and Cloud By Request - This article was written for the Atlassian server and data center platforms but may also be useful for Atlassian Cloud customers. If completing instructions in this article would help you, please contact Atlassian Support and mention it.
The following error occurred in the Mail Handler Configuration Page:
Tested the connection to the mail server and it was successful.
- After Upgrade from JIRA 6 to Jira 7
Incorrect Proxy/SSL configuration.
Confirm if Proxy/SSL configuration is actually the one causing this problem. It can be solved by bypassing proxy/SSL as per this KB: How to bypass a reverse proxy or SSL in Application Links and add a bare minimum HTTP connector to your server.xml.
Restart your JIRA instance for this connector to take effect.
Once done, access JIRA using *http://<ip address>:<port>*. This should *not* re-write/re-direct the URL.