As an administrator, I do not want to be required to input an email address for a JIRA user. Requiring an email has resulted in email spamming and looping when you have email via comments setup.

First issue.
Since you cannot remove a user that is associated with any item, you have to replace the email with something If they are invalid and someone puts a comment on a page, and notification services are utilized for notifying people involved - then it sends an email to this invalid user. This results in a reply that you have sent to an invalid user which is added as a comment on the issue since it replied back to JIRA and includes the JIRA issue in the subject. Since this invalid email comment is added to this issue, it sends another email out....thus, a loop of emails that is never ending

Second issue.
We have set up some generic users to identify roles. For example, we setup users for roles of implementation manager, integration engineer, developer, etc. This identifies who is responsible for the issue and indicates whose role it is in queue for. Then, as in KanBan model, you pick up from the top of what is available and assign it to yourself. Thus, you can always see what is ready for that role and assigned/not assigned; these are also often used when we set up template issues/subtasks. Then, once cloned, they will make the specific assignments.

Again, these generic role users require a user ID. We set them up with a valid email that is aliased. However, whomever it is aliased to must now manage that inbox to delete the emails as they are really invalid emails.

The preference is 1) either make the email address an option for an admin to identify as required or not or 2) not make it required as all.

Either way, it puts the option into the hands of the customer administrator to understand what happens if they don't input an email (e.g. that person doesn't receive email notifications) which, in my opinion, is pretty clear and self-explanatory. However, by not requiring it, you avoid all of the email spam and additional management.