Attachment Hell with emailed comments - Ignore email icons when auto-importing attachments from email replies

We use email as a method for adding comments to JIRA issues.  This is an excellent method for tracking issue history, especially in "business" projects that are big on communications.  User can send emails and CC a JIRA email address to add it to a comment. Sweet. Regular users have an embedded code in their signatures and we use the "Add a comment before a specified marker" handler to truncate the user signature and message history from the saved JIRA comment.

This generally works well but it a problem with some users eg external consultants and occasional users who don't who don't use the truncation code.  An email may have one or often several images plugged into their signature, like a company logo, a facebook logo, a think-before-printing message, etc.  With an email history, they may be adding a bunch of both their and others logos in one easy/nasty hit.

In these cases, a large number of attachments can build up via an email exchange making the "real" issue content hard to see.  These are a ***** grind to delete.  To delete, the user must click the bin icon, then wait for the confirmation screen, then click ok.  That's not a problem one-off but extremely slow and frustrating for deleting 20 attachments.

Solution 1: (quick) Allow attachments to be checked and bulk deleted on the attachments page.

Solution 2 (much better!) : Use a hash to detect duplicate attachments and only display the latest on the main issue page.  Duplicates are displayed in the attachments window and a single "Delete duplicates" button click kills all but the most recent version.

Solution 3 (even better!)  In addition to detecting and displaying only the latest attachment as above, allow attachments to be marked as junk.

Once marked as junk:

1. They are not displayed on the main issue page at all, significantly reducing clutter.
2. Only a single copy is kept, and this is shown in a new "junk" section/link on the attachments page.  (Marked: "These attachments are never displayed or retained")
3. It should be possible to unjunk an attachment to allow it to be displayed from then on.

To work really nicely, the junk attachments list would be be global across the project.  If this is an issue, maybe a switch could control it?  (Allowing junk declarations across the whole instance would be quite spiffy for those pesky facebook icons but might be considered a bit of a bit of a risk and generate an authorisation problem...)

Automatic removals could be logged for audit purposes if this doesn't clutter the activity log.  And the don't delete anything that is not in the junk library rule means that there is always a copy available if it is actually required.