Hello everyone, I find some strange log.
The environment is Debian5_64 zcs6.0_OSE.
Mails from xxxxx@qq.com are all tagged to be failed in /var/log/zimbra.log.
But I can receive these mails normally.
Mails from other domains are all ok.
Some log about this question.

Sep 26 11:44:43 mail amavis[5378]: (05378-02) dkim: FAILED, IN_FUTURE0 0:04:30) Author+Sender+MailFrom signature by i=@qq.com, From: <1303024032@qq.com>, a=rsa-sha256, c=relaxed/relaxed, s=s0907, d=qq.com, invalid (public key: OpenSSL error: bad base64 decode)
Sep 26 15:50:32 mail amavis[24530]: (24530-08) dkim: FAILED, IN_FUTURE0 0:04:31) Author+Sender+MailFrom signature by i=@qq.com, From: <35988944@qq.com>, a=rsa-sha256, c=relaxed/relaxed, s=s0907, d=qq.com, invalid (public key: OpenSSL error: bad base64 decode)
Sep 26 16:02:36 mail amavis[24530]: (24530-09) dkim: FAILED, IN_FUTURE0 0:04:25) Author+Sender+MailFrom signature by i=@qq.com, From: <21334878@qq.com>, a=rsa-sha256, c=relaxed/relaxed, s=s0907, d=qq.com, invalid (public key: OpenSSL error: bad base64 decode)

Is there anyone can give some suggestion ?