Let me try this again…
> Begin forwarded message:
> From: MAILER-DAEMON@mx.tcnc.com (Mail Delivery System)
> Subject: Undelivered Mail Returned to Sender
> Date: April 30, 2019 at 12:04:26 MST
> To: firstname.lastname@example.org
> This is the mail system at host mx.tcnc.com.
> 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
> <email@example.com>: host mx.contesting.com[2001:470:1:313::220] said: 550
> 5.7.1 Service unavailable; client [2600:3c03::f03c:91ff:fe0c:9b6] blocked
> using zen.spamhaus.org (in reply to RCPT TO command)
> Reporting-MTA: dns; mx.tcnc.com
> X-Postfix-Queue-ID: 3CCF52071
> X-Postfix-Sender: rfc822; firstname.lastname@example.org
> Arrival-Date: Tue, 30 Apr 2019 19:04:19 +0000 (UTC)
> Final-Recipient: rfc822; email@example.com
> Original-Recipient: rfc822;firstname.lastname@example.org
> Action: failed
> Status: 5.7.1
> Remote-MTA: dns; mx.contesting.com
> Diagnostic-Code: smtp; 550 5.7.1 Service unavailable; client
> [2600:3c03::f03c:91ff:fe0c:9b6] blocked using zen.spamhaus.org
> From: Paul <email@example.com>
> Subject: Ceiling Fans
> Date: April 30, 2019 at 11:56:44 MST
> To: firstname.lastname@example.org
> I am replacing an indoor ceiling fan and thought I might call on the RFI
> audience to share their experience with regular electric motors versus the
> newer DC motors. I am drawn to the energy efficiency of the latter but fear
> the control electronics may be RFI noisy as are our baneful “wall worts”.
> So, anyone have an opinion ?
RFI mailing list