What is the Host not Found error about?

This message is sent back to you from the SMTP server. The server is telling you that the “host” you tried to send e-mail to does not exist. The “host” is the domain name proceeding the “@” in the e-mail address. In the case of jason@dogbits.com, the host would be dogbits.com. If you tried to send a letter via Postal mail to a non- existant address, the letter would eventually come back to you with “address unknown” stamped on it. Similarly, if the host does not exist, e-mail cannot be delivered, and it is returned to the sender with a similar message. You will need to verify the spelling of the domain name. Make sure this domain name exists (is registered and in use) or mail sent to this domain will continue to bounce.