If you are getting following error with email while receiving emails
2007-01-03 14:14:33 1H2BZ9-0007EK-HY => [email protected] R=lookuphost T=remote_smtp
2007-01-03 14:15:05 H=web32905.mail.mud.yahoo.com [184.108.40.206] F= rejected RCPT : web32905.mail.mud.yahoo.com [220.127.116.11] is currently not permitted to relay through this server. Perhaps you have not logged into the pop/imap server in the last 30 minutes or do not have SMTP Authentication turned on in your email client.
For the above error please check the entry of domain in /etc/localdomains of the server.
#grep domain.com /etc/localdomains
If the entry is missing then you get such an error. The domain must be in ‘/etc/localdomains’, once it has been placed there the error should disappear.