Redmine

With some system, registered customers can send bugs, features, help requests .. by sending emails. Admins will classify email into Issue type, assign to staffs and create a new Issue. Emails will be sent to all concerned people with a subject like that [PRJ1-BUG-1234] Bug on forms . People will have 2 ways to update issue: on the Redmine or by sending email with subject [PRJ1-BUG-1234] Some thing to say.... When Redmine receive the incoming email, base on the information in the subject, it can add the content of email to the issue.
I want this feature very much but I cannot because I am not familiar with Ruby. My customers prefer sending email than accessing to the website.
Thanks,