Hello,
im trying to solve this problem, my server, is sending email to domain qq.com, many mails follow some logs:
postfix/error[15120]: AC23E6CC99A: to=<1149401400@qq.com>, relay=none, delay=38287, delays=38283/3.9/0/0.06, dsn=4.4.2, status=deferred (delivery temporarily suspended: lost connection with mx3.qq.com[183.62.125.223] while performing the HELO handshake)

Need help.