When I am an assignee to an issue, I oftenly need to ask somebody about someting via e-mail so that my e-mail and responce became a comments to the issue.
It would be nice to introduce separate operation like "send e-mail", when I would be able to type target address manually. It is also sufficient that reply to such e-mail be acceptable by standard comment logger service whether my addressee is known to JIRA or not (at least one time).
This would give very flexible way to geather information to the issue and the like.

Additional details
1. It seems reasonable having separate permission to perform such action
2. It would be convenient to have separate template for such e-mails

– Andrey Khapugin