OS Ubuntu 6.06
Zimbra 6.0.5

After upgrade from 5.0.20 to 6.0.5 i try send mail to hotmail and gmail. Hotmail can send but gmail cannot send. when i see in logs file it show as below

<user@google.com>: host google.com.s9a1.psmtp.com[] said: 550 5.2.1 <user@google.com>... Mailbox disabled for this recipient (in reply
to RCPT TO command)