Hello Andreas, Citing RFC 3464 Section 2 Paragraph 4: "The From field of the message header of the DSN SHOULD contain the address of a human who is responsible for maintaining the mail system at the Reporting MTA site (e.g., Postmaster), so that a reply to the DSN will reach that person. Exception: if a DSN is translated from a foreign delivery report, and the gateway performing the translation cannot determine the appropriate address, the From field of the DSN MAY be the address of a human who is responsible for maintaining the gateway."
https://datatracker.ietf.org/doc/html/rfc3464#section-2 And I can understand Google here, as we do it similar, if a Message does not contain a "5322" valid From Header we reject the message. (or sometimes deliver to spam folder for analysis) The Amount of Mails with malformed From Headers that are SPAM is so much higher compared to DSNs that we think protection oft he user against spam is more important than a not arriving DSN... And as there is no sane default, perhaps the Postfix Config needs a breaking change fort he default that forces mailops to add the right value... -----Ursprüngliche Nachricht----- Von: mailop <[email protected]> Im Auftrag von A. Schulze via mailop Gesendet: Freitag, 13. August 2021 16:46 An: [email protected] Betreff: [mailop] GMAIL reject Bounces Hello, Sometimes messages are accepted by an MX but undeliverable in later processing. Misconfigured forawarding, User broke it's sieve rules, whatever In this case the LDA send a DSN back to the sender. But if the sender uses gmail.com, the DSN will never arrive: Aug 13 16:09:15 mta postfix/smtp[105040]: 4GmQQz2MM8zB08wK: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[142.251.5.26]:25, delay=0.26, delays=0.01/0/0.13/0.12, dsn=5.7.1, status=bounced (host gmail-smtp-in.l.google.com[142.251.5.26] said: 550-5.7.1 [redacted_ipv4] Messages missing a valid address in From: 550 5.7.1 header, or having no From: header, are not accepted. a185si1555216wme.53 - gsmtp (in reply to end of DATA command)) well, it's postfix that generated this DSN with this RFC5322.From From: MAILER-DAEMON (Mail Delivery System) This wasn't configured by me but is Postfix default since two decades - https://github.com/vdukhovni/postfix/blob/v1.1.0/postfix/src/bounce/bounce_notify_util.c#L268 - https://github.com/vdukhovni/postfix/blob/master/postfix/proto/bounce#L76 Should I really tell my customers "gmail break email" ? I would like to here your opinions. Andreas _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
