Yahoo rejecting email due to Spamhaus block
Can you please investigate why Yahoo is rejecting emails from me?
This is the mail system at host smtp28.relay.iad3a.emailsrvr.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
firstname.lastname@example.org: host mta7.am0.yahoodns.net[220.127.116.11] said: 553 5.7.1
[TSS07] Connections will not be accepted from 18.104.22.168, because the
ip is in Spamhaus's list; see
https://help.yahoo.com/kb/postmaster/SLN5070.html (in reply to MAIL FROM