2023-05-10 03:49 に Andrew Hodgson wrote:
Sendgrid is maintaining the Message-Id header which is good for archiving. It is re-writing the Return-Path header though which means that bounce handling in Mailman won't work, but I think all the services do this in some way so I am happy to live with that for the moment.
How does it rewrite the Return-Path? Returned mail is not something that such a service would be able to handle properly (although they can help with apparently returned spam). If mail is legitmately sent and returned as undeliverable, only the author or their agent will know how to handle it. So such services should provide some way to find out about returned mail.
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