For account creation, user must enter valid email address and then confirm that address with click on link provided in welcome message, but, Yahoo email servers rejecting all messages from valdea.com domain with this error:
SMTP error from remote mail server after pipelined MAIL FROM:<dmaMods@valdea.com> SIZE=2187:
553 5.7.2 [TSS06] All messages from 18.104.22.168 will be permanently deferred; Retrying will NOT succeed.
We tried everything to fix this problem, all parameters on mail server and DNS servers are correct, we asked yahoo administrators for help, but problem persist.
Finally, there is no other way but disable all Yahoo emails and here is list of blocked domains: