Hello,
Thank you for contacting Yahoo Postmaster.
The error you’re getting is caused by an issue with your From address.
- These errors indicate that the domain used to the right of the @ in the MAIL FROM does not appear to be a real domain.
- We determine if the domain name exists by using an SOA query; therefore, if multiple subdomains are used in MAIL FROM commands, then besides setting up a DNS A or MX record (perhaps using a wildcard), then SOA records must be set up as well.
- This error can be returned as either a timeout/servfail (451) or a permfail (554)
You’ll need to work with your provider to make sure your From address meets these requirements to resolve the error.
Thanks for understanding.
Have a great day!
Warm regards,
Emilia
Yahoo Postmaster
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正常情况soa记录应该是dns自动配置的，可能有些不是主流dns服务商没做好导致soa缺失了，补上就好了