On Sun, 9 Jul 2017, Wietse Venema wrote:
Jul 7 23:10:57 bear postfix/smtp[29598]: 92F8422A0C90: to=<a...@xyz.com>,
relay=aspmx.l.google.com[2607:f8b0:400d:c0b::1a]:25, delay=0.65,
delays=0.13/0/0.29/0.22, dsn=5.7.1, status=bounced (host
aspmx.l.google.com[2607:f8b0:400d:c0b::1a] said: 550-5.7.1
[2607:f308:1:1::2 12] Our system has detected that this message
550-5.7.1 is likely unsolicited mail. To reduce the amount of spam sent to
550-5.7.1 Gmail, this message has been blocked. Please visit 550-5.7.1
https://support.google.com/mail/?p=UnsolicitedMessageError 550 5.7.1 for
more information. o74si4960796qkl.67 - gsmtp (in reply to end of DATA
command))
Was your mail really sent from 2607:f308:1:1::212? According to DNS,
your primary MX is bear.techie.net, with IP addresses 205.134.185.202
and 2607:f308:1:1::2.
If may be worthwhile to fix the SMTP client IP address with
"smtp_bind_address6 = 2607:f308:1:1::2", at least for off-site
email.
No, it's sent from 2607:f308:1:1::2. I don't know what the extra spaces +
12 after the IP address mean in that error report from gmail.
Scott