Allow configuring service desk issue title

Problem to solve

Currently, a service desk issue is created with the following title: Service Desk (from <sender>): <subject>. I find this problematic because also the subject the sender receives in e-mail notification then uses this as a subject instead of original subject. Moreover, including sender's e-mail address in the issue title can be problematic from sender's privacy perspective.

User experience goal

I would like (that it is possible to configure) that the sender receives e-mail with subject Re: <subject>.

Proposal

I have two proposals. First is to simply change the default:

• Instead of using Service Desk in issue title, allow one to configure a label to apply to those issues (by default a label with name Service Desk). I think the only reason why that prefix exists is to differentiate those issues. But labels are much better tool for that.
• Instead of putting e-mail address into the title, associate e-mail address of the sender (and everyone CCed) using a dedicated new model fields associated with the issue. Those fields would be always seen as sensitive and never made public, even if the issue itself is public. All those addresses would get notifications about issue changes. This would address also the following issues:
  • #4652 (closed)
  • #195372 (closed)
  • #12243 (closed)

Another solution is to simply make the title configurable using some template. Moreover, the issue template should support a placeholder for the sender e-mail address. Then I could configure the title to be just Re: <subject> and copy the e-mail address into the description of the issue.