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To be clear, Jira is responsible for the definition/connectivity of mail hosts. When a mail has been successfully retrieved, then JEMH is invoked (by Jira), and at his point our support scope begins.
We try to be helpful, and offer suggestions - our support is best effort as this This problem area is not in our support scope. Problems with the Jira platform should be directed to support.atlassian.com. We try to help and offer suggestions as our support is best effort.
JEMH Server / DC
We have documented the impact of Basic Auth deprecation for JEMH Server/DC in the following blog, with steps to resolve Inbound Mail retrieval issues related to Authentication.
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