from our side we're pretty sure that there are NO malformed headers in our customers messages to gmx recipients. As we use well-known software like postfix. Time of servers is sync to ntp too. It started all over sudden yesterday evening at about 16:45 CET. Several of our outbound service ips affected. We do not have bigger mailflow to gmx compared to the past. Sound to me that a new feature has been implemented that need some fine tuning by a big hammer ;-)
> Ensure that the following email headers included in your message are syntactically correct: Date, From, Sender, To. think sender is only mandatory if multiple From header senders are present. If there is only one From header sender then the Sender header is **not** mandatory. See RFC5322 Section 3.6.2 > If the originator of the message can be indicated by a single mailbox and the author and transmitter are identical, the "Sender:" field SHOULD NOT be used Also take note of the note in RFC regarding the absence of Sender header (same section) > The absence of the "Sender:" field is sometimes mistakenly taken to mean that the agent responsible for transmission of the message has not been > specified. This absence merely means that the transmitter is identical to the author and is therefore not redundantly placed into the "Sender:" > field. Cheers tobi p.s. we have a lot of very disappointed customers which (at least quite a bunch of them) are as well gmx users On 3/12/21 1:58 PM, Hans-Martin Mosner via mailop wrote: > Am 12.03.21 um 11:53 schrieb Arne Allisat via mailop: >> Sorry. Me again. >> >> Two things: Some people experience temp rejects with an c=irlims message.I >> thought that is your case as well, but it >> isn’t. >> >> In your case it is an c=hi and you are pointed to the „Sending mail to GMX“ >> page >> (https://www.gmx.net/mail/senderguidelines/ >> <https://www.gmx.net/mail/senderguidelines/>), right? >> That means one or more of your header are malformed. >> >> First three bullets of that page tell you exactly what to do. >> >> //Arne >> > As I wrote "as far as we can see, we're not doing anything wrong" :-) Of > course I checked the bullet points. > > * Make sure that your mail server and client time and date are correctly > set as specified in RFC 5322 > <https://tools.ietf.org/html/rfc5322#section-3.3>. > > This is a postfix system, I'm pretty certain Wietse wouldn't let any code > into postfix that does not conform to RFCs. > The server has an NTP-synchronized clock as every server should, and of > course the dates and times are right (names in > Received: header are munged by mailu to protect user's privacy): > > Received: from authenticated-user (PRIMARY_HOSTNAME [PUBLIC_IP]) > by mail.heeg.de (Postfix) with ESMTPA id AF05C7360002; > Fri, 12 Mar 2021 09:41:34 +0000 (UTC) > Date: Fri, 12 Mar 2021 10:41:34 +0100 > > * Ensure that the following email headers included in your message are > syntactically correct: Date, From, Sender, To. > > From: User <[email protected]> > Subject: Re: topic > To: [email protected]=29?= <[email protected]> > Cc: "[email protected]" <[email protected]> > > There is no Sender header, AFAIK it is not mandatory. > > * Make sure that the following headers included in your email are limited > to just one each: BCC, CC, Date, From, > Sender, Subject, To. > > That's the case. No duplicate headers there. > > As I said, it would be REALLY helpful if the error message included some hint > about what is considered wrong. This whole > "check whether you did something wrong, here are the rules" when your system > already knows or believes to know what I > did wrong isn't helpful. If you insist that giving out that information to > potential spammers is a dangerous thing then > your support should bite the bullet and provide the necessary information > when they get a problem report. > > Cheers, > Hans-Martin > > > > _______________________________________________ > mailop mailing list > [email protected] > https://list.mailop.org/listinfo/mailop _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
