JIRA does not have a specific functionality for create new users through e-mail, but you can configure the JIRA Mail Handler to create a new user when an email which is not registered in JIRA is used to create a new issue.
You can get further information about the JIRA mail handler in this KB https://confluence.atlassian.com/display/JIRA/Creating+Issues+and+Comments+from+Email#CreatingIssuesandCommentsfromEmail-Createanewissueoraddacommenttoanexistingissue
Notice that this can be not the perfect workaround for what you want, as you would need to create a new issue to create a new user.
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