I have been struggling with this. I 'm using the Jira Cloud (Free).
I have tried to invite another user to my jira however no email was received. I have tried using different email addresses from different domains for the invitation but nothing works.
The success notification was displayed in jira however nothing was really sent.
As this is free, there's no official support for users; and none of the suggested tips from the community has worked as they revolve around engaging with the jira support team.
any tips?