NOTE: This suggestion is for JIRA Server. Using JIRA Cloud? See the corresponding suggestion.
The ability to email a issue (attachments and all) to a outside person that does NOT have a jira user account would be extremely handy according to our developers.
Send notification / comment to specific user
Email To Feature
Add the ability to send the issue to one or more users
Ability to add watchers during issue creation
Adding a user to a watchers list should cause an email notification
Email issue to external person
CC email address list in issues (notify arbitrary emails)
E-mail this issue operation
Issue operation plugin
Include attachments or link to attachments in notification emails