Undelivered Mail Returned to Sender

[Mail Delivery System]

This is the mail system at host server.freestyler.rs.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<simonaliapis at gmail.com>: host
    gmail-smtp-in.l.google.com[2a00:1450:400c:c0c::1b] said: 550-5.7.1
    [2a01:4f8:151:9150::2] Our system has detected that this message does
    550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and
    550-5.7.1 authentication. Please review 550-5.7.1
    https://support.google.com/mail/?p=IPv6AuthError for more information 550
    5.7.1 . k62si17049436wmk.189 - gsmtp (in reply to end of DATA command)
-------------- next part --------------
An embedded message was scrubbed...
From: "=?utf-8?B?54aK55yJ?=" <pkg-llvm-team at lists.alioth.debian.org>
Subject: 3661961613SwjKZCleNM大酬宾，来就給18⒏菜今~伽魏#新ds6969006要不JIA企鹅1991900074王芝604953；c o m                            
Date: Thu, 27 Dec 2018 11:20:12 +0800
Size: 6141
URL: <http://alioth-lists.debian.net/pipermail/pkg-llvm-team/attachments/20181227/130db52e/attachment-0001.mht>