Address space for IPv6 is so huge, that it's almost impossible to keep IPv6 reputation data, and sender authentication is usually required. for IPv6 host Under normal conditions, SPF and DKIM are used to authenticate sender, but if you forward messages without address rewrite, all forwarded messages fail SPF authentication and only DKIM-signed messages are authenticated. You can try to:
1. Implement SRS to provide SPF authentication for forwarded messages (you will share SRS domain's reputation with forwarded messages). 2. Switch to IPv4 to have IP reputation both cases can dramatically affect deliverability of direct mail from your server, because quality of forwarded messages will affect reputation of your domain in (1) and IP in (2). You should only do it if you have good protection against fake/spam messages and you do not forward any spam. If you still want to use forwarding, consider using dedicated domain for (1) and dedicated IPv4 for (2). But if you forward spam, expect the same issue again. 08.11.2017 22:20, Warren Volz пишет: > > All, > > One of my users has their account setup to forward mail to Gmail. > Recently I've started to see lots of rejects that look like the following: > > <us...@gmail.com> (expanded from <us...@somelocaldomain.net>): host > gmail-smtp-in.l.google.com[2607:f8b0:400e:c04::1a] said: 550-5.7.1 > [ipv6 address 18] Our system has detected that > 550-5.7.1 this message is likely suspicious due to the very low reputation > of 550-5.7.1 the sending IP address. To best protect our users from spam, > the 550-5.7.1 message has been blocked. Please visit 550 5.7.1 > https://support.google.com/mail/answer/188131 for more information. > p26si2014836pli.781 - gsmtp (in reply to end of DATA command) > > I've looked over the forwarding best practices provided by google and > we are not modifying the envelope sender. I'd rather not start > throwing away what our filter marks as spam since I leave that up to > the user, but is that the only way to stop the bounces? Also, is the > "18]" an artifact or some kind of error? > > Thanks for the help. > > -Warren > > > > _______________________________________________ > mailop mailing list > mailop@mailop.org > https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop -- Vladimir Dubrovin @Mail.Ru
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