On Sat, Mar 12, 2022 at 09:03:37AM +0100, Matthias Apitz <g...@unixarea.de> wrote:
> El día viernes, marzo 11, 2022 a las 03:12:41p. m. +0100, Stefan Hagen > escribió: > > > > I've been seeing a lot of that lately. Google seem to have tightened > > > their email security practice recently. > > > > > > It appears that 1blu is doing something that GMail doesn't like. They > > > probably have a number of users who have the same problem. I would > > > ask them to check their MTA configuration against the section "Make > > > sure your messages are authenticated" in the referenced page > > > (https://support.google.com/mail/answer/81126#authentication). > > > > > > > 550-5.7.26 This message does not have authentication information or > > > > fails to > > > > 550-5.7.26 pass authentication checks. To best protect our users > > > > from spam, the > > > > 550-5.7.26 message has been blocked. Please visit > > > > Authenticated in this context means, you don't have SPF / DKIM / DMARC set > > up. > > > > You can use this service: https://www.mail-tester.com to test your > > setup. It provices you an email address. Send an email to it > > and then your mail and server setup will be evaluated. > > Thank you, Stefan. > > I did such a test and the result can be seen here: > https://www.mail-tester.com/test-ahwup3i9z > > > This is an example from me: > > https://www.mail-tester.com/test-3ghr082f2 > > > > Feel free to examine it and set your host up in a similiar way. > > As far as I understand all the changes can't be done on my host (a > laptop). I send mails with mutt and mutt with sendmail to smtp.1blu.de > > And I'm afraid, if I contact the support of 1blu I don't know if they will > react (I've mixed experience from the past). I will give it a try... > > Thanks > > matthias > > -- > Matthias Apitz, ✉ g...@unixarea.de, http://www.unixarea.de/ +49-176-38902045 > Public GnuPG key: http://www.unixarea.de/key.pub So it looks like the real problem might be "You're listed in 1 blacklist" (http://www.backscatterer.org). Try to get removed from it. Good luck. It sounds like the mail server you are using needs a configuration change to stop backscatter. Perhaps you could direct your mail server providers to that site. cheers, raf
