I am a Jira admin and started to add 2 users to watch an issue in my project but there have 1 user not receiving any notifications mails for the issue update and comments added to the issue. When I checked the notification scheme "all watchers" are added to receive mail notifications when there is an comment added and updated in the issue.
All the other team members are receiving the mail notifications who are watching the same issue. Sadly I am the admin of the project as well.
Don't know why the user can't able to receive the email notification.