Today my boss complaint that some mail from partners sending with gmail.com has not received. Then I go through the log and found:

Feb 8 07:14:06 mx postfix/smtpd[30146]: connect from mail-qc0-f182.google.com[209.85.216.182]
Feb 8 07:14:06 mx postfix/anvil[14352]: statistics: max connection rate 3/60s for (smtp:202.181.213.164) at Feb 8 07:13:59
Feb 8 07:14:06 mx postfix/anvil[14352]: statistics: max connection count 3 for (smtp:202.181.213.164) at Feb 8 07:13:59
Feb 8 07:14:06 mx postfix/anvil[14352]: statistics: max cache size 7 at Feb 8 07:05:17
Feb 8 07:14:07 mx postfix/smtpd[30146]: NOQUEUE: filter: RCPT from mail-qc0-f182.google.com[209.85.216.182]: <wong@gmail.com>: Sender address triggers FILTER smtp-amavis:[127.0.0.1]:10026; from=<wong@gmail.com> to=<monica@beautiful.com> proto=ESMTP helo=<mail-qc0-f182.google.com>
Feb 8 07:14:07 mx postfix/smtpd[30146]: NOQUEUE: filter: RCPT from mail-qc0-f182.google.com[209.85.216.182]: <wong@gmail.com>: Sender address triggers FILTER smtp-amavis:[127.0.0.1]:10024; from=<wong@gmail.com> to=<monica@beautiful.com> proto=ESMTP helo=<mail-qc0-f182.google.com>
Feb 8 07:14:07 mx postfix/smtpd[30146]: 124B12E0F1B: client=mail-qc0-f182.google.com[209.85.216.182]
Feb 8 07:14:08 mx zmconfigd[25747]: Watchdog: service antivirus status is OK.
Feb 8 07:14:08 mx zmconfigd[25747]: All rewrite threads completed in 0.00 sec
Feb 8 07:14:08 mx zmconfigd[25747]: All restarts completed in 0.00 sec

It looks like to me the Sender address has been blacklisted by the system.

Anyone know what is this and how to release the blacklist?

Many thanks