I would like to know why Jira Service Desk will not create a ticket from email when the Subject line is empty

[Nic Brough -Adaptavist-]

JIRA has a handful of "fields" that are absolutely mandatory.  Project, issue key, issue type are generally handled for you, but it absolutely must have a "Summary"

When importing email, it reads the subject line for the summary (a logical UI choice in my opinion), so if a user leaves the subject blank, it has nothing to put in the summary

An arguable fix would be to dummy string in for these cases, something like "User has neglected standard netiquette and left the most useful part of the email blank", but the standard handlers just fail and reject the email.