The primary purpose of Redmine is a project management tool.
However it can be used as a help desk solution with a little configuration.
The key is setting up Redmine to receive e-mails.
My personal approach is to set up the e-mail retrieval as IMAP. This way you could set up a new account help@example.com and any incoming messages are sent to a project of your designation.
See the documentation for the most up to date information. Now when a user or anyone sends an e-mail to help@example.com a new issue with a set status is created. Future correspondence via the issue are automatically added.
Thanks for the brief intro.
Do your customers have the ability to log into your Redmine install?
Yes, but none do. They prefer the e-mail exchange format.
E-mail goes into auto-magic issue creation. As we update they get additional e-mails to which they can then reply logging against an issue.