Why does DenyHosts report “Error sending email”?
Depending on your particular email server you may see an error message such as: Error sending email {‘foo@localhost’: (504, ‘DenyHosts>: Sender address rejected: need fully-qualified address’)} If you do receive this error message simply edit your configuration file and enter a fully qualified email address for the SMTP_FROM parameter. For instance: SMTP_FROM = DenyHosts nobody@yourdomain.
Depending on your particular email server you may see an error message such as: Error sending email {‘foo@localhost’: (504, ‘: Sender address rejected: need fully-qualified address’)} If you do receive this error message simply edit your configuration file and enter a fully qualified email address for the SMTP_FROM parameter.