The JIRA Advanced Mail Handler is an extension of the standard Atlassian JIRA email handler; it allows users to define many fields of the newly created issue (reporter, project key, type, priority, affected components, etc.) directly in the body of the email message. Hence, one of its notable features is that you do not need to repeat the whole process (opening a mail account on your mailserver, creating a mail account in JIRA, associate a handler service to the mail account and configure it) for each project you have in your JIRA installation; you just do the process once, setting a global mail account and handler service that will receive messages for all projects.
This JIRA add-on was originally developed at CERN by Daniele Raffo and distributed under an open-source license.
Full documentation and details can be found here: