Sending email problems: Relay access denied

[jaffaizal]

Falko/Till,

Me and my clients are having problems sending email to say, gmail and yahoo.
Also a few other email address:

salleh@matrade.gov.my
cmkasule@nssfug.org
mfaicsl@yahoo.com


Tried to send a test email to my gmail account (jaffaizal@gmail.com ). Got the following error message:

Sending failed:
Message sending failed since the following recipients were rejected by the server:
jaffaizal@gmail.com (The server responded: "<jaffaizal@gmail.com>: Recipient address rejected: Relay access denied")
The message will stay in the 'outbox' folder until you either fix the problem (e.g. a broken address) or remove the message from the 'outbox' folder.
The following transport protocol was used:
PLANIMA

Your help is appreciated.
JafFaizal