I have Zimbra 5.01GA FOSS on Ubuntu 6.06LTS. When I try sending mail from my PDA using the SMTP server (zimbra) I get the following error message:

Feb 8 22:06:24 mail postfix/smtpd[20801]: NOQUEUE: reject: RCPT from apn-89-223-245-75.vodafone.hu[]: 554 5.7.1 <taqr22@ise.u-szeged.hu>: Relay access denied; from=<mko@clover.com> to=<taqr22@ise.u-szeged.hu> proto=ESMTP helo=<Inbox>

How can I enable zimbra to accept the SMTP connection? I think if I were to enable SSL it might work. The PDA is a WindowsMobile6.

Can anyone help me?