T he following Exim mail servers error was encountered while sending out mails. The original error was experienced by Gravity Forms WordPress plugin. However, I was able to test it out by using command line to rule out the plugin.
email@example.com R=virtual_aliases: No Such User Here
The debug message I received via Gravity Forms is the following. This confirms the mail has been passed on from WordPress to the mail server.
2016-03-25 11:06:04.042599 - DEBUG --> GFCommon::send_email(): Result from wp_mail(): 1 2016-03-25 11:06:04.042748 - DEBUG --> GFCommon::send_email(): Mail was passed from WordPress to the mail server. 2016-03-25 11:06:04.153172 - DEBUG --> GFFormDisplay::handle_confirmation(): Sending confirmation.
Before I go any further, I would like to give some background information on domain.com, which the following aspects are hosted as below.