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If the All users may send emails option is enabled, all users may send emails. However, if the option is set off then Jira Administrators may grant permissions in the JIRA Jira Permission Schemes.
Send Issues in Email Permission
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To access the configuration screen and the Emails menu in JIRAJira's top navigation bar, users must be JIRA Jira Administrators or JIRA Jira System Administrators.
Future versions of Email This Issue will declare a new Global Permission type so that Email This Issue configuration may be delegated to privileged users.
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