553 Relaying disallowed

Hi,

when something sending mail to me.. they are getting error

Message not delivered

There was a problem delivering your message to support@faretofly.com. See the technical details below, or try resending in a few minutes.

The response from the remote server was:

553 Relaying disallowed

I am able to send mails from my account "support@faretofly.com" but not able to receive any mail