I use the emails from JIRA to alert me when there is new activity on tickets I am the assignee for. However, I also receive many emails for all the tickets I am simply a watcher on (which I still want). It would be nice if the JIRA email included a tag in the header that specified the reason "I" am receiving the email. i.e.
Send_Cause=watcher|assignee|reporter
I could then easily filter my email based on the Send_Cause.
I might eventually break the old-fashioned email habit - but I don't know of a way to highlight tickets with unseen comments/changes, so I use my email's inbox for this purpose.