Here is the problem I am having. Whenever one of my clients is trying to send an email to a particular email address, they are getting the following error message:
[remote address] SMTP error from remote mailer after RCPT
host [remote host] [remote ip]: [local machine name] [sender ip]:33447 is currently not permitted to
550-relay through this server. Perhaps you have not logged into the pop/imap
550-server in the last 30 minutes or do not have SMTP Authentication turned on
550 in your email client.
Any ideas as to what might be happening? I've checked that the domain name exists in /etc/localdomains.