They're internal state passing and encrypted data. iirc smtp-source is used for internal delivery latency metrics, and the other is more esoteric.
Brandon On Fri, Apr 29, 2022 at 5:53 PM Al Iverson via mailop <[email protected]> wrote: > Anybody familiar with the Gmail headers X-Gm-Message-State and > X-Google-Smtp-Source? A coworker asked about them, but I am not really > familiar. Figured I'd see here if anybody knows anything about them. > Thanks in advance for your thoughts or feedback! > > Cheers, > Al > > -- > > Al Iverson / Deliverability blogging at www.spamresource.com > Subscribe to the weekly newsletter at wombatmail.com/sr.cgi > DNS Tools at xnnd.com / (312) 725-0130 / Chicago (Central Time) > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop >
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