Desperate ~ mail error Relay access denied

[Helga]

I am new to linux and also new to ZIMBRA
my mail server is working fine for all the accounts but one (1)
everyone can send and recieve except one account
taht account can only recive because when he sends the reponse for is


554
<xxxxxx@XXXXX.net>:
Relay access denied


please help me let me know what to do

PS: i don't know if this helps but i also don't have my certificates installed
i bought my certificates at godaddy but when i tried to install them the system crashed so i took them off

[mmorse]

If in /var/log/zimbra.log it looks like
NOQUEUE: reject: RCPT from something.domain.com 554 <account@domain.com>: Relay access denied; with maybe like from= to= proto=ESMTP helo= or proto=SMTP helo= on the end
see: ZimbraMtaMyNetworks - ZimbraWiki

for the cert see: Commercial Certificates - ZimbraWiki