The documentation seems to suggest this is NOT possible:
This message handler creates a new issue, or adds a comment to an existing issue. If the subject contains an issue key, the message is added as a comment to that issue. If no issue key is found, a new issue is created in the default project.
https://confluence.atlassian.com/jira/creating-issues-and-comments-from-email-185729464.html#CreatingIssuesandCommentsfromEmail-Addacommentfromthenonquotedemailbody mentions three handlers that only comment, without create.
Hi Community! I’m Elaine, Confluence Product Manager. You may have read my earlier post about page tree in space navigation sidebar. I'm excited to share another improvement that helps you organize ...
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