I was working with Aminul Islam to resolve an issue with the installation of Signature-WP. He asked for my server credentials but when I tried to send them I got an error where the mail delivery failed.
Delivery to the following recipient failed permanently:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain codexcoder.com by codexcoder.com. [184.108.40.206].
The error that the other server returned was:
550 No Such User Here”